Manual de servicio serie mz40 de baic

1
Contents
ChapterIVehicleIntroduction2
1.1Vehiclebirth3
1.2Vehicledimensions4
1.3Vehicleidentification5
1.4Technicalcharacteristicsofvehicleintroduction6
1.5Technologyrelatedtovehicleandconfigurationparameters7
1.6Vehicleintroductionandfieldoperationpracticeform12
ChapterIIEngine13
2.1Engineoverview14
2.2Mechanicalessentialsofengine16
2.3Enginemanagementsystemessentials25
2.4ContinueVariableValveTimingsystem(CVVT)30
2.5Exhaustgasrecirculationsystem（EGR）33
2.6Fieldoperationpracticeformofengine34
ChapterIIIBodyelectric40
3.1Vehiclepowerdistributionandbonding41
3.2Lightingsystem43
3.3Wiperwashingsystem49
3.4Instrumentcluster51
3.5Centralcontroldoorlockingsystem53
3.6Powerwindow57
3.7Electricrearviewmirror58
3.8Airconditioningsystem59
3.9Fieldoperationpracticeformofbodyelectric63
ChapterIVtransmissionandchassissystem65
4.1MR510D05transmission66
4.2Chassissystem69

2
Chapter I Vehicle Introduction

3
1.1 Vehicle birth
•
MZ40 is the self-owned brand cross-type vehicle (mini vehicle) developed by the BAIC Motor to meet the market demand.
•
MZ40 refers to the world leading vehicle manufacturing experience, based on the world leading Toyota Town Ace Van platform, and the whole vehicle is optimized by engineers from Asia and Europe. Apply 26 important improvements and 343 common improvements to adapt to the Chinese road condition, set the new standard for passenger car class wide mini vehicle.
1.1.1 MZ40 vehicle
1.1.2 MY39、MY40 vehicles
•
MY39 and MY40 vehicle are developed by BAIC Yinxiang in accordance with market demand. Together with MZ40, they jointly form the complete product production line.
•
MY39 and MY40 vehicle adopt some advanced technology of the existing auto sector and integrates advantages of the mini car, such as novel and unique exterior design, flat body floorboard, spacious interior space, safe and cozy drive, fuel efficiency, less emission and contamination; it presents advanced level in terms of fuel consumption, emission, reliability, safety, etc.
MZ40
Toyota Town Ace Van
Unveiled in the domestic market in April, 2011
MY39
MY40

4
1.2 Vehicle dimensions
1.2.1 MZ40 vehicle dimension
1.2.2 MY39、MY40 vehicle dimension
Height: 1878mm
Width: 1600mm
Wheelbase: 2500mm
Longth: 3895mm
Wheelbase: 2630mm
Longth: 4022mm

5
BJ6400L3R
BJ6400V3R
MZ40 Product model
Position: under the front windshield glass
1.3 Vehicle identification
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
Manufacturer (LNB)
Vehicle type
The total vehicle length and seat number
Body type
Type of power and energy
Transmission brake and operation safety constraint type
Check digit
Year
Assemble plant
Production sequence number
•
VIN code is composed of 17 characters; therefore, it's usually called as 17-digit code. It includes the vehicle manufacturer, year, vehicle, body type and code, engine code, assembly location and other information. The correct understanding on VIN code is of utmost importance for us to correctly identify vehicle as well as correct diagnosis and maintenance.
The meaning of VIN:
VIN identification information
Position：above the right front headlamp（MZ40）
Nameplate information of the vehicle

6
1.4 Technical characteristics of MZ40 vehicle introduction
Body structure:
•
The nose adopts the energy adsorption safety design, with energy adsorption area dimension larger than the same class, including thicker anti collision steel grid. Thus, the energy arising out of the collision may be absorbed to the maximum extent to effectively protect safety of pedestrian, driver and passenger.
•
The body adopts bird nest type Power Cage structure, surrounding seat cabin, more structural reinforcement and design of roof and floorboard with rebar; the body frame is stronger and reliable; adopt Baosteel cold milled steel plate, highly strong, rigid, safe and corrosion resistance; the side bumper is equipped to reinforce side collision capacity to offer more safe protection to passenger. In terms of power train:
•
Adopt mature and reliable 1.3L LJ474 engine or 1.2L A12 engine independently developed b BAIC Motor, which is leading in terms of power train, affordability and environmental protection amidst engine of the same category. In terms of body electric:
•
Reach sedan-level configuration, central control door lock, power window, electric rearview mirror, headlight height adjustment, dual evaporator air conditioning, MP3, high brake lamp, etc are all available. In terms of chassis:
•
Adopt mature and reliable structure, namely front McPherson independent suspension, rear longitudinal spring leaf dependent suspension. It ensures comfort and enhances carrying capacity; the brake system adopts the front disc and rear drum structure, etc.
Standard configuration MP3
Dual evaporator air conditioning
High brake lamp
Rear wiper with water spraying
BSS body safety structure
Front McPherson suspension disc brake
Rear steel plate suspension drum brake
Headlamp height adjustment
Power window
Electric rearview mirror
FSS front safety structure
LJ474/A12 engine
Central door locking

7
Items
Basic type
Comfortable type
Luxury type
Seat number
8-seat
7-seat
7-seat
Vehicle body size (length/width/height/wheelbase)
4030163619072700
Front wheel span
1386
Rear wheel span
1408
Equipment weight Kg
1185
Full load weight kg
1850
Minimum turning diameter m
10.4
Maximum speed Km/h
130
Fuel tank
45L
Constant speed oil consumption at fifth gear (without AC equipment)
5.5L
Tire model
175/70R 14LT
1.5.1 MZ40 whole vehicle technical parameters
1.5 Technology related to vehicle and configuration parameters
Engine Model
LJ474Q3E2
BSE A12
Type
Four-in-line, 16 engine valves, Single Overhead Camshaft, cogged belt driving, electric control multi-point oil injection
Four-in-line, 16 engine valves, Dual Overhead Camshaft, Chain drive, electric control multi- point oil injection engine, CVVT, EGR
Compression ratio
9.5:1
10:1
Displacement
1.298L
1.198L
Maximum power(kw/r/min)
60.5 /6000
63.5/6000
Maximum torque(N ·m/r/min)
102/3000-3500
108/4000
Constant speed fuel consumption（ 50km/h）
≤6.4L/100KM
Oil consumption limit for comprehensive working conditions
≤8.6L/100KM
Output per litre（kw/L ）
45
53
Fuel number
No worse than unleaded No. 93 petrol (GB17930-1999）
No worse than unleaded No. 93 petrol (GB17930-1999）
Displacement standard
National IV
Euro IV
Product model
BJ6400L3R
BJ6400V3R
Brake system (front/rear)
Front disc and rear drum
Suspension system (front/rear)
Macphersan
Plate spring （5片）
Steering system
Rack and pinion mechanical steering device
Safe and energy absorbing steering column
Driving brake system
Hydraulic dual circuit brake system
Parking brake system
Manual mechanical zipper type parking brake
Drive method
Middle placed rear drive

8
1.5.2 MY39/MY40 whole vehicle technical parameters
MY39 Product model
BJ6390AHZ1A
BJ6390AHW1A
Power assembly
1.0MT
1.3MT
Model
Basic/comfortable/luxury
Size MM
3895x1600x1865/1878
3895x1600x1878
Wheelbase MM
2500
2500
Wheel span (front/rear) MM
1310/1310
1310/1310
Minimum clearance to the ground (no load) MM
152
145
Minimum turning radius
4.95
4.95
Equipment weight Kg
1060
1060
Tire specifications
165/70 R13LT
165/70 R14 LT
165/70 R14 LT
Seat number
5-8
5-8
MZ40 Product model
BJ6400AJZ1A
BJ6400AJW1A
Power assembly
1.0MT
1.3MT
Model
Size MM
4022x1600x1865
4022x1600x1878
Wheelbase MM
2630
2630
Wheel span (front/rear) MM
1310/1310
1310/1310
Minimum clearance to the ground (no load) MM
152
145
Minimum turning radius
5.45
5.45
Equipment weight Kg
1100
1100
Tire specifications
165/70 R13LT
165/70 R14 LT
Seat number
5-8
5-8

9
Engine Model
B10X
B13X
Engine type
Four-in-line
Four-in-line
Displacement CC
1000
1342
Maximum output KW/RPM
45
69
Maximum torque N.m/rpm
87
115
Compression ratio
10:1
9.5:1
Maximum speed Km/h
120
130
Transmission type
Five-gear manual transmission
Five-gear manual transmission
Fuel tank volume L
40
40
Constant speed oil consumption at 60km/h L/100Km
5.3
5.5
Emission
National IV
National IV
Product model
BJ6390AHZ1A
BJ6390AHW1A
Brake system (front/rear)
Suspension system (front/rear)
Macphersan
Macphersan
Steering system
Rack and pinion mechanical steering device
Safe and energy absorbing steering column
Driving brake system
Hydraulic dual circuit brake system
Parking brake system
Manual mechanical zipper type parking brake
Drive method

10
Secondary program
3-level program
MY39 basic edition
MZ40 basic edition
MY39 comfort edition
MZ40 comfort edition
MY39 luxury edition
MZ40 luxury edition
Power-assisted steering (electric)
○
—
○
—
○
—
Air conditioning
○
○
●
●
●
●
High back with headrest for copilot, 4-direction to adjust
Front and back cannot be adjusted
●
—
—
—
—
—
Front and back can be adjusted
—
●
●
●
●
●
High back with headrest for driver, 4-direction to adjust
Front and back cannot be adjusted
—
—
—
—
—
—
Front and back can be adjusted
●
●
●
●
●
●
Intermediate seat
Joint seats with low back
●
●
—
—
—
—
Joint seats with high back and headrest
—
—
●
—
●
—
Separate seat with high back and headrest
—
—
—
●
—
●
1.5.3 MY39 and MZ40 vehicle configuration contrast
Rear seat
Low back and without headrest
●
●
●
●
High back with 2 headrests
●
●
Imitation leather seat cover from original factory
—
—
—
—
●
—
Radio
With MP3/USB socket
●
●
●
●
—
—
CD
—
—
—
—
●
●
Front door glass
Manual
●
●
●
●
Electric
—
—
—
—
●
●
Rear side window
Butterfly-like open
●
●
●
●
●
●
Loud speaker
2
2
4
4
4
4
Sun shield
1
1
2
2
2
2
The front seat belt
Three-point seat belt
●
●
●
●
●
●
The intermediate seat belt
2 sets of three-point seat belt
●
●
●
●
●
●
The rear seat belt
2 sets of three-point seat belt
●
●
●
●
●
●
Electrically adjustable headlamps
—
●
—
●
●
●
The steering column lock
●
●
●
●
●
●
Door reflector
—
●
—
●
—
●
Child-Proof Rear Door protection lock
●
●
●
●
●
●
Rear wiper
—
—
—
—
●
●
Safety handle
3
3
5
5
5
5
Fender
○
—
●
—
●
—
High brake lamp
●
●
●
●
●
●
Front fog lamp
○
○
●
●
●
●
Door lock
Central controlled
—
—
—
—
●
●

11
The front grille
Black
●
●
—
—
—
—
Same color
—
—
●
—
●
—
Uniform color
—
—
—
●
—
●
Bumper
Black
—
—
—
—
—
—
Same color
●
●
●
—
●
—
Uniform color
—
—
—
●
—
●
The rear license lamp cover
Black
—
—
—
—
—
—
Same color
●
●
●
●
●
—
Chromium plated
—
—
—
—
—
●
Outside handle
Black
●
●
—
—
—
—
Same color
—
—
●
●
—
—
Chromium plated
—
—
—
—
●
●
Outer rearview mirror
Black
—
—
—
—
—
—
Same color
●
—
●
—
●
—
Manual with same color and side turn signal lamp
—
●
—
●
—
—
Electric side steering signal lamp with same color
—
—
—
—
—
●
Wheel hub
Steel
●
●
●
●
—
—
Steel wheel trim cover
—
—
●
●
—
—
Aluminium alloy
—
—
—
—
●
●
Central stainless steel rails of the sliding door
●
●
●
●
●
●
•
Icon instruction: ●standard configuration ○selected configuration —no configuration like this (the red part is the higher part for MY39, yellow part for MZ40)
•
Note 1: same color means the component (or assembly) has the same color as the vehicle body; Uniform color means the component (or assembly) has the uniform color.

12
1.6.1 Field operation on vehicle
Field practice purpose and requirements
•
Get familiar with structural characteristics of MZ40 vehicle.
•
Get familiar with MZ40 vehicle configuration. Preparations of field practice tools
•
Two MZ40 vehicles, one MZ40 vehicle maintenance manual, one set of normal disassembly tool, two operation lamps, one lifter, one barometer, tire inflator and tool vehicle, one special diagnostic instrument for BAIC Weiwang, two special high impedance ammeters for vehicle, several pairs of glove and cloth. Field practice item (operation duration 15 minute)
•
With response to the relevant configuration of the vehicle for field practice, tick (√) after the letter when the relevant configuration is available, or else, present (×)
B-standard configuration MP3
A-Dual evaporator air conditioning
Ｍ-High brake lamp
L-rear wiper with water spraying
Ｋ-BSS body safety structure
Ｉ-Front McPherson suspension disc brake
Ｊ-Rear steel plate suspension drum brake
E-Headlamp height adjustment
D-Power window
F-Electric rearview mirror
Ｇ-FSS front safety structure
Ｈ-ＭＺ４０/A12 engine
C-Central door locking
Ａ
Ｂ
Ｃ
Ｄ
Ｅ
Ｆ
Ｇ
Ｈ
Ｉ
Ｊ
Ｋ
Ｌ
Ｍ
Tailing work after finishing the field practice
•
Resume the former vehicle state.
•
Count and put away tools and clean the practice field.
Operation standard compliance assessment
Item accuracy assessment
1.6 Vehicle introduction and field operation practice form

14
2.1.1 Overview of engines equipped on MZ40
MZ40
A12
LJ474Q3E2
2.1 Engine overview
LJ474Q3E2 engine
•
Liuji together with the famous electric control company UAES developed the mini auto engine with domestic advanced level.
•
And it widely matches many domestic mini vehicle companies.
A12 engine
•
A new engine with 1.2L displacement, and it’s self-developed by BAIC.
•
This engine adopts technologies such as Multi-Point Fuel Injection, Static ignition distribution, intelligent variable valve timing, exhaust gas recirculation. The dynamics, economy and environmental protection reach a leading position among similar engines.
2.1.2 Engine exterior contrast
LJ474Q3E2 engine
A12 engine

15
2.1.3 Technical parameter contrast of engine
Items
A12parameters
LJ474parameters
Displacement
1.198L
1.298
Valve amount
16
16
Camshaft
DOHC
SOHC
Variable valve timing system
Equipped with CVVT
N/A
Exhaust gas recirculation system
Equipment
N/A
Maximum power(kw/r/min)
63.5/6000
60.5 /6000
Maximum torque(N ·m/r/min)
108/4000
102/3000-3500
Output per litre（kw/L）
53
45
Idling speed（r/min）
750 ?0
750?0
Oil level (L)
3.5
4.2 (New oil filter)
The amount of coolant (L)
6.3-6.5
4.6
Environmental protection index
Euro IV
National IV
LJ474Q3E2 engine
A12 engine

16
2.2.1 Mechanic structure characteristics of LJ474Q3E2 engine
2.2 Mechanical essentials of engine
The drive camshaft adopts timing toothes belt.
Single Overhead Camshaft (SOHC)
16 valve design
Special alloy cast aluminum crankshaft
Wholly forged crankshaft
Intake manifold with circulating hot water
•
The circulating hot water runs through the intake manifold , increases the intake temperature to promote the fuel’s vaporization and make sure they are well distributed. The coolant of small cycles runs through the throttle valve, and guarantees that the throttle valve is ice free in cold weather.
•
The support of the single overhead camshaft and rocker shaft and cylinder head form an entirety. Therefore, the structure is very firm. It greatly reduces valve mechanism noise and quantity of valve mechanism components to make the engine structure more compact.
•
The intake and exhaust hole adopts cross flow type; the valve is installed on "V" structure. Adopt intake valve with guide screen and tangential airway; the spiral airway can generate intake swirl to make the mixture evenly and adequately mixed; both the volumetric and ventilation efficiency are very high.
•
The crankcase is made of special alloy cast aluminum. It has very deep rebar to make the structure stronger.
•
The crankshaft is forged in its entirety. It's supported by five bearing to minimize vibration impact during operation.
•
The camshaft drive mechanism adopts toothed timing belt. Ensure low noise during engine operation.

17
2.2.2 Mechanic structure characteristics of A12 engine
Timing chain drive
Dual Overhead Camshaft (CVVT)
Continue Variable Valve Timing system (CVVT)
16 valve design
Plastic intake manifold
Cast iron cylinder block
Aluminum cylinder head
EGR system
•
The hollow chilled cast iron camshaft is used; the camshaft journal has the lubricant hole.
•
The timing chain is the silent toothed chain; compared with the belt drive, the chain drive is more reliable and the life is longer.
•
A12 engine adopts intake side continuous variable valve timing (CVVT); the optimal valve phase position may be obtained according to the engine operation state to optimize the intake volume, improve fuel efficiency, emission and fuel affordability performance.
•
The equipped EGE system may help to reduce nitrogen oxide (NOx) in the exhaust gas and help to improve fuel affordability during partial load.
•
A12 cylinder head is cast by aluminum alloy via gravity, four cylinders and 16 valves; the combustion chamber above the cylinder head is ridge shaped.
•
The plastic intake manifold adopted may greatly reduce vehicle weight, effectively reduce intake resistance and improve inflation efficiency; meanwhile, adopt CAE to analyze and calculate the optimized intake tube shape and length and optimize combustion to improve affordability and emission performance.

18
LJ474 engine timing mark
2.2.3 Valve timing issue
Note: the fourth cylinder is at the compression TDC
Whether the crankshaft timing gear mark “”is in line with the oil pump convex point mark “↓”
Whether the camshaft timing gear mark “E”is in line with the mark “V”on the cylinder head cover
•
The vehicle has four timing marks; the crankshaft timing mark is indicated by “I ”and “↓”; the camshaft timing gear mark is indicated by “E”and “V”.
•
When mounting timing belt, well align the mark before mounting; the specific mark alignment method is shown as per the diagram above.
•
If the timing mark is not aligned, rotate the crankshaft clockwise to align the two marks; however, the allowed scope shall not be exceeded.
•
When the timing belt is dissembled, to turn the camshaft and crankshaft beyond the scope shown as per the diagram is strictly prohibited. During operation, the interference between the piston and valve may possible damage related component of piston and valve.

19
A12 engine valve timing
•
When mounting the crankshaft timing sprocket, the corresponding well aligned timing mark corresponds to the top dead centre of the cylinder 1 piston
•
Mark 1 on sidebar of the timing chain (sidebar of the first blue unit clockwise) should align with the groove mark on CVVT camshaft sprocket on the intake side.
•
Mark 7 on sidebar of the timing chain (sidebar of the second blue unit clockwise) should align with dot mark on camshaft sprocket on the exhaust side
•
Crankshaft timing sprocket mark should align with the sidebar marked as 34 on the timing chain (sidebar of the third blue unit clockwise)
•
The timing mark on crankshaft damping pulley should align with the mark on sprocket chamber cover (after aligning the chain timing mark)

20
Adjust and measure the intake valve clearance
Adjust and measure the exhaust valve clearance
•
Precautions: When check the valve clearance, you should put the thickness gauge between the base circles of cam and rocker arm.
Position
Cold state
Thermal state
Intake valve clearance
0.13～0.17 mm
0.17～0.21 mm
Exhaust valve clearance
0.23～0.27 mm
0.27～0.31 mm
LJ474 Valve clearance examination and adjustment
2.2.4 Valve clearance issue
A12 Valve clearance examination and adjustment
Valve clearance adjustment standard:
•
Intake valve 0.2 ±0.05mm
•
Exhaust valve 0.3 ±0.05mm
Calculate the newly installed valve tappet thickness:
•
Intake valve: A = B + (C -0.2 mm)
•
Exhaust valve: A = B + (C -0.3mm) (A：newly mounted valve tappet thickness B: dissembled valve tappet thickness C: measured valve clearance)
Wall thickness

21
Main shaft bearing bush selection of LJ474 engine crankshaft
2.2.5 Bearing bush selection issue
Related identification of LJ474 main bearing bush matching
•
The main bearing cap for various cylinders shall not be confused; crankshaft main shaft journal group number+ main shaft bore diameter group number +main bearing bush group number =7
Main shaft bearing bush grouping matching table: (matching clearance 0~0.02 mm)
Crankshaft main journal outer diameter group
Main bearing bush group
Main bearing hole inner diameter group

22
A12 main bearing bush matching
Main bearing bush label
Crankshaft main journal diameter（mm）
Group
1
2
Size range
47.991~48.000
47.982~47.991
Identification
1
2
Main bearing hole diameter（ mm）
Group
Size range
Identification
Group identification
Size range
Size range
1
52.000~52.009
1
1
Green
Bearing bush thickness1.983~1.988
Clearance0.024~0.052
2
Yellow
2
52.009~52.018
2
2
Yellow
3
Blue
Related identification of A12 main bearing bush matching

23
A12 connecting rod bush matching
Connecting rod bush label
Bearing bush thickness（mm）
Diameter of the journal of crankshaft connecting rod（mm）
Group
1
2
Size range
37.991~38.000
37.982~37.991
Identification
A
B
Big end hole diameter of the connecting rod（mm）
Group
Size range
Identification
Group identification
Size range
Size range
1
41.000~41.009
A
1
Green
2
Yellow
2
41.009~41.018
B
2
Yellow
3
Blue
Related identification of A12 connecting rod bush matching

24
2.2.6 A12 Engine cooling system issue
Water outlet seat
Big circulation heat radiation
Small circulation flow direction
Big circulation flow direction
Water pump
Water pump belt pulley
82℃ Thermostat
78℃ Thermostat
Replace
•
During maintenance on the cooling system of the vehicle equipped with A12 engine, since A12 engine coolant emission method is not mastered, the air is not fully drained before completing the cooling system maintenance to finally lead to high water temperature of engine.
•
For the vehicle equipped with A12 engine, the thermostat with cooling system will start at 78℃. Be inconsistent with the thermostat for vehicle equipped with LJ474 engine; the incorrect thermostat mounted may lead to high water temperature of the engine.
High water temperature confirm:
•
Confirm the vehicle manual brake has been pulled up; when the gear is in neutral position, make ignition and start the engine; keep operation under the idle speed till the cooling fan begins to operate; observe dashboard water temperature indication signal and fan operation state:
•
If the fan closes within one minute after operation and the instrument water temperature reading is sustained at 5-6 lattice and wait for re-operation of the fan. If the fan secondary operation also closes in one minute and the water temperature reading is sustained at 5-6 lattice, the water temperature is judged not to be high;
•
If the fan keeps on running and instrument water temperature reading continues to rise till alarm, make immediate flameout and the water temperature is judged to be high; when the interior antifreeze cools till no burn risk on human body, proceed to the procedure of coolant injection and air drainage.

25
2.3 Engine management system essentials
2.3.1 List of engine control systems
•
LJ474Q3E2 adopts United Electronics M7-Motronic engine management system United Electronics actually uses Bosch electronic control system. It's a set of advanced engine management system. It takes the engine electric control unit (ECU for short) as the control center, measures the various engine working parameters by sensors mounted at different positions, follows the control program set by the ECU, controls the fuel injection volume and ignition advance angle accurately, enables the engine to work at the best performance under different working conditions, that is, the best power output, the most economical fuel consumption and minimum exhaust gas.
•
A12 engine adopts the EASY‐U1.12 engine management system from continental automotive electronics, it consists of sensors, engine ECU and actuators, and controls the intake air volume, injection volume and ignition advance angle.
A12
Continental EASY-U1.12
LJ474Q3E2
UAES M7-Motronic
UAES

26
2.3.2 LJ474 M7-Motronic engine management system
LJ474 M7 engine management system block diagram
EMS
Actuator
Sensor
Fuel injector
Throttle valve position sensor
Intake pressure temperature sensor
Engine coolant temperature sensor
Speed sensor
Phase sensor
Front oxygen sensor
Ignition coil
Knock sensor
Idling stepper motor
Canister control valve
Rear oxygen sensor
UAES

27
Circuit diagram of LJ474 M7 engine management system:
Ignition coil-1
Ignition coil-2
Fuel injector
Canister solenoid valve
To instrument P23
Oil pump
To instrument P24
Bonding
Clutch coil of Air- conditioner Compressor
Fan of water tank
Condenser fan
From generator
From wind speed switch
Air conditioner pressure switch
EMS (Engine Management System)
Front oxygen sensor
Rear oxygen sensor
Phase sensor
Coolant temperature sensor
To instrument cluster 14
Air conditioner temperature sensor
Send engine failure sensing to instrument cluster 9
Knock sensor
Speed sensor
Idling stepper motor
Vehicle speed and mileage sensor
To instrument cluster 11
To instrument cluster 6 (speed output)
Diagnosis interface
Power source to RF05
Bonding point -9
Bonding point -8

28
2.3.3 A12 EASY-U engine management system
EASY-U engine management system block diagram
Oil injection timing and its time of duration
Ignition coil charging time and ignition advance angle
Idling stepper motor control
Canister control valve opening
Heated Oxygen sensor control
EGR valve opening degree control
Main relay control
Oil pump relay control
Air conditioner compressor relay control
High and low cooling fan relay control
VVT actuator control signal
The engine speed outputs to instrument
Fault lamp control
ECU
Intake pressure signal
Intake temperature signal
Throttle valve position signal
Coolant temperature signal
Crankshaft angle signal
Camshaft phase signal
Front-Oxygen-Sensor signal
EGR valve position signal
Air conditioner request signal
Air conditioner Evaporator temperature
Power-assisted steering switch signal
Knock signal
Vehicle speed signal
Rear-oxygen -Sensor signal
Fuel injector
Throttle body （MTB）
Fuel rail assembly (FRA)
Intake temperature and pressure sensor （TMAP）
Camshaft sensor (ACAM)
Ignition coil (ICM)
Upstream oxygen sensor（UPO）
Air filter
Downstream oxygen sensor （DNO）
Catalytic converters
Crankshaft sensor （MCPS）
Water temperature sensor （CTS）
Knock sensor (KS)
Canister control valve (CPV)
Canister

29
Circuit diagram of EASY-U1.12 engine management system:

30
2.4 Continue Variable Valve Timing system (CVVT)
•
A12 engine adopts Continue Variable Valve Timing system （CVVT）on the intake side, we can adjust the time and opening degree to open or close the intake valve according to the operation condition of the engine, to reach the best air quantity, improve the combustion efficiency, displacement and fuel economy.
2.4.1 System summary (A12 engine)
CVVT actuator
Advance control:
Delay control:
CVVT timing oil pressure control solenoid valve
2.4.2 CVVT timing oil pressure control solenoid valve
Armature
Iron pan
Roller valve
Spring
Coil
Sleeve
Oil filter
Terminal definition1. 12V power source2: Control signal
ECU
B_O4
1
2
Main relay
•
ECU controls the CVVT solenoid valve current by duty ratio signal, make the CVVT solenoid valve at different state to control the actuator and realize advance or delay control.

31
2.4.3 CVVT actuator
•
CVVT system adopts sprocket drive blade VVT module (CVVT actuator), adjusted phase angle : 21.5°±0.5°(camshaft rotation angle),engine control adjustable phase angle is 30°.
Valve lift
Exhaust valve lift curve
(Phase angle) 30°
Exhaust valve lift curve
(At maximum lag angle)
Exhaust valve lift curve(At maximum lead angle)
Overlapped part
Crankshaft angle
Phase angle adjustment 21.5°
Lead angle chamber
Lag angle chamber
At maximum lag angle
At maximum lead angle
Middle position

32
•
Continuous variable valve timing (CVVT) solenoid valve is controlled via ECU; ECU control signal adopts the form of duty ratio. Through different duty ratio, make continuous variable valve timing (CVVT) solenoid valve under three different stabilization states to thus control changeover of CVVT actuator under three different states.
Fuel supply
Fuel supply
Oil leakage
Oil leakage
Fuel supply
Fuel supply
Oil leakage
Oil leakage
Fuel supply
Maintain
Maintain
State I
State I I I
State I I
2.4.4 CVVT mechanical operation principle
Delay control state
Keep the control state
Advance control state
Blade
Rotation direction
Oil return outlet
Oil pressure
Engine ECU
Blade
Rotation direction
Oil return outlet
Oil pressure
Engine ECU
Camshaft timing oil control valve
Engine ECU
Oil pressure

33
2.5 Exhaust gas recirculation system （EGR）
•
EGR: Exhaust Gas Recirculation
•
Engine computer opens the EGR valve.
•
Monitor the EGR valve working condition by EGR valve position sensor, make sure the actual opening degree is the same as the targeted one.
•
Monitor EGR flow volume by MAP.
Engine exhaust gas
Engine intake
Recirculating exhaust gas
EGR valve opens
•
Under suitable working conditions, open EGR valve at a suitable degree, connect the exhaust pipe to intake manifold passages, guide the exhaust gas to intake manifold to mix with fresh air. Reduce nitrogen oxide (NOx) in the exhaust gas and help to improve fuel affordability during partial load. When the engine temperature is too high, the introduction of non-combustible exhaust gas in the cylinder may slow down combustion heat inside the cylinder and help to protect the engine.
ECU A_C4
ECU B_G3
ECU B_M1
Main relay
ECU B_N4
Terminal definition
1. 5V power source
2. Bonding
3. Position signal
4. 12V power source
6. EGR valve control signal
•
EGR valve coil resistor：8±0.5Ω
•
GR position sensor signal standard: 0.14V‐4.5V

34
2.6.1 Field operation on LJ474 engine element location
2.6 Field operation practice form of engine
•
•
•
Get familiar with electronic control element configuration and mounting location of MZ40 (equipped with LJ474 ) engine.
•
Get familiar with and master electronic control element disassembly method of MZ40 (equipped with LJ474 ) engine. Preparation of field practice material
•
One LJ474 engine assembly, one LJ474 engine maintenance manual, one set of normal disassembly tools, one special high impedance ammeter for vehicle, several pairs of glove and cloth. Field practice item (operation duration 15 minute)
•
According to the provided diagram, refer to the physical article and fill in the name of the corresponding elements (sensor, actuator) of the missing mark number in the according position. 1、_______________ 2、________________ 3、________________ 4、_______________ 5、________________ 6、________________ 7、_______________ 8、________________ 9、________________ 10、______________

35
•
•
•
Get familiar with configuration and mounting position of electronic control element of MZ40（A12） engine.
•
Get familiar with and master disassembly method of electronic control element of MZ40（A12）engine. Preparation of field practice material
•
One A12 engine assembly, one A12 engine maintenance manual, one set of normal disassembly tools, one special vehicle high impedance ammeter, several gloves and cloth. Field practice item (operation duration 15 minute)
•
According to the provided diagram, refer to the physical article and fill in the name of the corresponding elements (sensor, actuator) of the missing mark number in the according position. 1、_______________ 2、________________ 3、________________ 4、_______________ 5、________________ 6、________________ 7、_______________ 8、________________ 9、________________ 10、_______________ 11、________________ 12、________________ 13、______________
2.6.2 Field operation on LJ474 engine element location

36
•
Get familiar with and master test method of MZ40 engine actuation element.
•
Get familiar with and master standard data of MZ40 engine actuation element. Preparation of field practice material
•
Two MZ40 vehicles (one separate vehicle equipped with LJ474 engine and A12 engine) , one MZ40 maintenance manual, one special diagnostic instrument, two special high impedance ammeters for vehicle, four LED test lamps, several pins for circuit test, one roll of electrician tape, one set of normal disassembly tool, one rubber hammer, several pairs of gloves and cloth. Field practice item (operation duration 30 minute)
2.6.3 MZ40 engine actuator test
•
LJ474 engine ignition coil detection: insert the plug and open the ignition switch to measure voltage on both terminals of the ignition coil separately at ①_______V and ②_______V； remove the plug and open the ignition switch to measure voltage on both terminals of the ignition coil separately at ①_______V and ②_______V. It's thus judged that ①is____terminal and ② ____terminal of the ignition coil.
•
Fuel injector test: insert the plug and open the ignition switch to measure voltage on both terminals of the fuel injector separately at ① _______V and ②_______V；remove the plug and open the ignition switch to measure voltage on both terminals of the fuel injector separately at ①_______V and ②_______V. It's thus judged that ①is____terminal and ② ____terminal of the fuel ejector plug. Use the diagnostic instrument to observe the fuel injection pulse width during idle speed__ms, fuel injection pulse width at 2000RPM__ms.
Fuel injector1 2 3 4
From the 12V power source of RLY05 relay
Ignition coil-1
Ignition coil-2
EMS
E03
E07
•
•

37
•
Get familiar with and master test method of MZ40 engine sensor.
•
Get familiar with and master standard data of MZ40 engine sensor. Preparation of field practice material
•
Two MZ40 vehicles (one separate vehicle equipped with LJ474 engine and A12 engine) , one MZ40 maintenance manual, one special diagnostic instrument, two special high impedance ammeters for vehicle, four LED test lamps, several pins for circuit test, one roll of electrician tape, one set of normal disassembly tool, one rubber hammer, several pairs of gloves and cloth. Field practice item (operation duration 40 minute)
2.6.4 Field practice on MZ40 engine sensor test
•
Throttle valve position sensor test: remove the plug and open the ignition switch to measure voltage on three lines of the throttle valve position sensor separately at ①_______V , ②_______V, ③______V. Insert the plug and open the ignition switch to measure voltage on three lines of the throttle valve position sensor separately at ① _______V , ②_______V, ③______V. Through the above measuring, it's thus judged that ①is____line, ②____line, ③____line.
•
Intake pressure sensor test: insert the plug and open the ignition switch to measure voltage on each terminal of the intake pressure sensor separately at ①_______V, ②_______V, ③_____V and ④____V； remove the plug and open the ignition switch to measure voltage on each terminal of the intake pressure sensor separately at ①_______V, ②_______V, ③_____V and ④____V；measure voltage on each terminal of the intake pressure sensor during idle speed separately at ①_______V, ②_______V, ③_____V and ④____V It's thus judged that ①is____terminal, ②____terminal, ③____terminal, ④ ____terminal of the intake pressure sensor.
•
Crankshaft position sensor test: remove the plug and open the ignition switch to measure voltage on each terminal of the crankshaft position sensor separately at ①_______V, ②_______V, ③_____V. It's thus judged that the crankshaft position sensor is___type. Terminals are separately ____terminal, ____terminal, ____terminal.
EMS
E19 E59 E40 E25
1
2
3
4
EMS
E18 E26 E39
1
2
3
Speed sensor
EMS
1
2
3
E47 E46

38
•
•
•
Camshaft position sensor test: remove the plug and open the ignition switch to measure voltage on three lines of the camshaft position sensor separately at ①_______V, ② _______V, ③_____V. Insert the plug and measure voltage on three lines of the camshaft position sensor during idle speed separately at ①_______V, ②_______V, ③_____V. It's thus judged that the camshaft position sensor is___type, plug terminals are separately ____terminal, ____terminal, ____terminal.
•
Oxygen sensor test: insert the plug and open the ignition switch to measure voltage on each terminal of the front oxygen sensor separately at ①_______V, ②_______V, ③_____V and ④____V；remove the plug and open the ignition switch to measure voltage on each terminal of the front oxygen sensor separately at ①_______V, ②_______V, ③_____V and ④ ____V. It's thus judged that___and__terminal of the front oxygen sensor are both terminals of the heating line, ___and__terminal are both terminals of the sensor part. The engine model to be tested is ______________________________________：
EMS
1
2
3
Camshaft sensor (ACAM)
E
18
E42
E39
Front oxygen sensor
Rear oxygen sensor
EMS
E02
E39
E45
E29
E04

39
•
Get familiar with and master operation method of the special diagnostic instrument.
•
Get familiar with and master MZ40 engine data stream standard data and various data analysis. Preparation of field practice material
•
One MZ40 vehicle (equipped with LJ474 engine), oneＭZ40 maintenance manual and one special diagnostic instrument. Field practice item (operation duration 10 minute)
•
Read MZ40 engine data stream and complete the table below.
Name
Current value (idle speed)
Current value（2000±50rpm）
Battery voltage
Engine speed
Target idle speed (without compensation)
Target idle speed (with compensation)
Engine coolant temperature
Intake temperature sensor voltage
Intake manifold pressure sensor voltage
Intake volume
Target location of step motor
Throttle valve opening
Carbon canister control valve duty cycle
Ignition coil charging time
Average fuel injection pulse width
Cylinder 1 delay ignition knock control
•
Notice: avoid data capture skill during long-term data operation of the engine: record data stream during the corresponding state; view data based on the data playback; print the data on the instrument memory card. View data according to data record file.
2.6.5 Engine data flow record analysis
•
•

41
3.1.1 Fuse relay box
3.1 Vehicle power distribution and bonding
MZ40 vehicle power supply centre
3.1.2 Circuit diagram of ignition power source distribution
Central door locking
Front fog lamp
Master relay
Horn Brake
Indoor lamp, lamplet
Emergency lamp
Headlamp
Rear defroster
Spare
Spare
Relay of width lamp
Relay of headlamp
Relay of position IG2
Wiper intermittent relay
Oil pump
Compressor
Front oxygen sensor
Rear oxygen sensor
Ignition power source
Reversing lamp
Turn signal lampInstrument cluster
LighterRadio
Front wiper washing
Rear wiper
Power window
Air blower
Cooling fan
Fan of air- conditioning system
Main relay
Relay of rear defroster
Relay of fan of air-conditioning system
Fuel pump relay
Paddle
Fog lamp relay
Relay of cooling fan
Compressor clutch relay
Fusible line
Ignition switch
Relay of position IG2
Relay of width lamp
Battery
To starter
Bonding
Bonding point -4
Bonding point -3
Lighting control switch
Switch of headlamp and width lamp
Width lamp
Headlamp

42
3.1.3 Vehicle bonding points
Bonding function
•
Capable of saving material (copper wire, plastic insulation, etc), simplify circuit and meanwhile facilitate wiring and maintenance.
•
Provide a simple circuit for power equipment and transmission of sensor signal and form reference point related to voltage measuring.
•
The good bonding is one of main measures for suppressing electromagnetic interference of the vehicle. Normal faults concerning bad circuit bonding:
•
Start difficult, abnormal instrument reading, abnormal, intermittent fault, abnormal spark, vehicle jump during acceleration, fault after sudden collision.
•
Notice to prevent bad circuit bonding: don't flush the vehicle with high pressure water; clean and tighten the component with determined bad bonding and make bonding again.
Bonding point -7
Bonding point -3
Bonding point -1
Bonding point -2
Bonding point -4
Bonding point -8
Bonding point -15
Bonding point -14
Bonding point -6
Bonding point -5
Bonding point -13
Bonding point -12
Bonding point -9
Bonding point -10
Bonding point -11
Battery

43
3.2.1 Vehicle light list
3.2 Lighting system
3.2.2 Lighting control elements
Lighting combination switch
Flasher
Emergency lamp switch
Headlamp height adjustment switch
Fuse and relay box
Rear fog lamp switch
Brake lamp switch
Reversing lamp switch
Door lamp switch
Low-beam lamp
Width lamp
Turn signal lamp
High-beam lamp
Brake lamp
Width lamp
Reversing lamp
Turn signal lamp
Rear fog lamp
Side turn signal lamp
Front fog lamp
High brake lamp
Indoor lamp
License lamp

44
3.2.3 Circuit diagram of headlamp height adjusting
Relay of width lamp
Relay of headlamp
Headlamp height adjusting switch
Combination switch
Relay of headlamp
Combination switch
Dimmer switch
Dimmer switch
Front fog lamp switch
Width lampHeadlamp
Width lamp
Headlamp
Left front low- beam lamp
Right front low- beam lamp
Left front high- beam lamp
Right front high- beam lamp
Left headlamp height adjusting motor
Right headlamp height adjusting motor
Bonding point -3
Bonding point -2
Bonding point -1
Bonding point -3
Bonding point -1
Bonding point -2
Bonding point -3

45
3.2.4 Circuit diagrams of turn signal lamp and hazard warning lamp
Emergency switch
Terminal
State
Red
Flash relay
Combination switch
Turn signal lamp switch
Left steering
Right steering
From the central control lock module (left turning)
To the left turn signal indicator lamp on the instrument cluster
Turn signal lamp, left front
Turn signal lamp, left
Turn signal lamp, left rear
Turn signal lamp, right rear
Turn signal lamp, right
Turn signal lamp, right front
To the right turn signal indicator lamp on the instrument cluster
From the central control lock module (right turning)
Bonding point -1
Bonding point -3
Bonding point -6
Bonding point -7
Bonding point -4
Bonding point -3
Bonding point -2

46
3.2.5 Circuit diagram of front and rear fog lamps
Relay of width lamp
Relay of headlamp
Combination switchLighting control switch
Dimmer switch
Width lamp
Headlamp
Terminal
State
Rear fog lamp
Left front fog lamp
Right front fog lamp
To instrument cluster
Bonding point -6
Bonding point -3
Bonding point -4
Bonding point -1
Bonding point -2

47
3.2.6 Circuit diagram of brake lamp and reversing lamp
To EWS engine management system 17
To engine
Reversing lamp switch
Brake lamp switch
Reversing lamp
Left brake lamp
High brake lamp
Right brake lamp
Bonding point -7
Bonding point -6
Bonding point -6
Bonding point -7

48
3.2.7 Circuit diagram of roof lamps
Rear indoor lamp
OFF
OFF
ON
ON
Central door locking system ON
Central door locking system ON
To the central door locking
Bonding point -1
Front indoor lamp

49
•
MZ40 vehicle of standard configuration is only equipped with the front wiper and washer system.
•
The luxury configuration is equipped with rear wiper/washer system
3.3 Wiper washing system
3.3.1 Description of wiper and washer system
Wiper motor
Rear wiper arm
Washing kettle and washing motor
Wiper arm and washing nozzle
Rear washing nozzle
3.3.2 Composition of the wiper and washer system
•
Wiper combination switch, wiper relay, wiper motor, water spraying motor, etc.
Front wiper motor
Water spraying motor
Rear wiper motor
Wiper/washer switch
Fuse and relay box

50
3.3.3 Circuit diagram of wiper and washer system
Via motor bracket bonding
Front wiper motor
Front washing motor
Rear wiper motor
Via motor bracket bonding
Rear wiper motor
Bonding point -4
Bonding point -1
Combination switchLighting control switch
Wiper switch
Front water spraying
Rear water spraying
Wiper intermittent relay

51
3.4 Instrument cluster
Instrument cluster includes:
•
Pointer type tacho (highest graduation: 180km/h).
•
LCD displays engine speed, fuel, water temperature, clock, total mileage and subtotal mileage; adjust clock and mileage switch and subtotal clearing via operating the regulation rod.
•
It's equipped with engine oil pressure alarm lamp, battery recharging indicator lamp, engine fault alarm lamp, brake fault alarm lamp, water temperature high alarm lamp, left and right steering indicator lamp, high beam indicator lamp, front fog lamp indicator lamp.
3.4.1 Description of instrument cluster:
Fuel volume indication
Fuel volume warning
Accumulative distance/Trip distance
High coolant temperature warning
Water temperature indication
Engine speed
Clock indication

52
3.4.2 Circuit diagram of instrument cluster
To the central door locking 9
To the electric rearview mirror A2
To the emergency switch 3
Fuel volume sensor (positive)
Fuel volume sensor (negative)
Simulation bonding inside the instrument cluster
Bonding point -4
Instrument backlit lamp
Coolant temperature, fuel volume, clock speed, distance
Speedometer
Low engine oil pressure warning lamp
Brake fault warning lamp
Battery charging indicator lamp
Indicator lamp for front fog lamp
Engine fault lamp
Left turn signal indicator lamp
Right turn signal indicator lamp
Normal temperature of coolant
Abnormal temperature of coolant
Double color lamp
Engine oil pressure switch
Switch, parking brake
Brake fluid level switch
From generator
From combination switch
From E09
From E20
From the speed sensor 3
From the left turn signal lamp
From the right turn signal lamp
From engine coolant temperature sensor 702
From combination switch 1298
Bonding point -1

53
3.5 Central control door locking system
Central control lock controller
Fastener (four valves)
Remote key
Turn signal lamp
3.5.1 System composition and principle
•
MZ40 high configuration vehicle is equipped with the central control door lock system; the system is composed of the central control lock controller, locker, remote control key, indicator (turn signal lamp) and related circuits.
•
The central control lock controller receives signal from the remote key and door lock switch and control the fastener to realize unlocking/locking function. Press the Unlock key on the remote controller, the doors will be unlocked, and the left and right turn signal lamps will each flash twice. Press the Lock key on the remote controller, the doors will be locked, and the left and right turn signal lamps will each flash once. When the door is not fully closed, press remote lock and door lock, the turn signal lamp doesn't flash. When the remote locking is enabled, in case of door opening, the turn signal lamp flashes 30 times. At ignition ON gear, the remote control unlock/lock has not motion.

54
3.5.2 Circuit diagram of central door locking system
Central door locking module
Left front door lock motor
Right front door lock motor
Left door lock motor
Right door lock motor
Door lock switch
Door lock switch
To right turn signal lamp
Bonding point -3

55
Proceed to learning code:
•
Within 10S, put ignition switch ON/OFF 6 times and then place it ON, the turn signal lamp flashes one time; in 5S, put the ignition switch OFF and then place the ignition switch ON; the turn signal lamp is lit again and keeps ON; prompt to proceed to learning code state; Learning process:
•
After accessing the learning code state, press any key of the remoter to learn the system; learn one remoter at a time; the cornering lamp is off once one remoter is successfully learned; the system may learn two remoters at most; in case of learning the remoter of or above three, make rollover erasion of the learned remoter in order. Exit from the learning state (If the system exits from the learning state, the turn signal lamps will go out.)
•
The learning code state only lasts 10S. 1) If the system detects no valid remote controller within 10s, it will exit from the learning state. 2) Successfully learn one remoter in 10S, immediately exit learning code state; 3) The ignition switch is on OFF and immediately exit learning code state;
3.5.3 Remote controller learning

56
•
There are two suppliers of MZ40 central door lock controller and remote control chip. They shall be used in match instead of interchanging.
3.5.4 Central control door lock system precaution
Wuhan Baode
Central control door lock controller Component number: 123787010
Remote control chip Component number: 123791010
Wuhan Baode
Hefei Softec
Hefei Softec
Central control door lock controller Component number: 128405404
Remote control chip Component number: 128405405

57
3.6.1 Power window description
•
MZ40 high configuration vehicle is equipped with the power window at the front driver side and passenger side. The power window system is composed of power window switch, power window control module, power window actuator and circuit.
3.6 Power window
Power window switch
Power window motor assembly
Power window control module
3.6.2 Circuit diagram of power window
Bonding point -4
Control module of right front power window
Switch of right front power window
Switch of left front power window
Control module of left front power window
Motor for lifting right front power window
Bonding point -4

58
•
MZ40 high configuration vehicle is equipped with the electric rearview mirror
•
The electric rearview mirror system is composed of electric rearview mirror assembly and electric rearview mirror switch. Each electric rearview mirror assembly has two motors. They can be turned on and off using the switch, to adjust the mirror in four directions: up, down, leftward and rightward, to provide sufficient field of view for the driver.
3.7 Electric rearview mirror
3.7.1 Discription of electric rearview mirror
3.7.2 Circuit diagram of electric rearview mirror
Power source for action
Power source for background lamp
Electric rearview mirror
Action
Pin
Action
Pin
Grounding wire
Grounding wire
Bonding point -3

59
•
The air-conditioning system of MZ40 vehicle is controlled manually. It is divided into two parts: the front air- conditioning system and the roof air- conditioning system
•
The front air-conditioning system performs the functions of air change, refrigeration and heating. The roof air- conditioning system performs only the function of air refrigeration.
3.8 Air conditioning system
3.8.1 Air conditioning system description
Dual evaporator air conditioning
3.8.2 Structural composition of A/C system
Condenser
Pressure switch
Air blower assembly
Compressor
Controller
Front evaporator assembly
Expansion valve
Roof evaporator assembly
Warm water valve

60
Rear evaporator
Front evaporator
Rear expansion valve
Expansion valve
Reservoir-dryer
Condenser
Compressor
Warm air inside the vehicle
Cool air
Ambient air
Cool air
Warm air inside the vehicle
Warm air
Low-temperature low- pressure gas
High-pressure medium- temperature liquid
High-pressure high-temperature gas
3.8.3 Double-evaporator air-conditioning refrigeration cycle diagram
•
The compressor is installed on the engine, and driven by belt. The condenser is installed in front of the radiator. The evaporator is installed in the vehicle body.
•
When the air-conditioning system is working, the low-pressure gaseous refrigerant from the evaporator flows through the compressor changing into high-pressure high-temperature gas. The gas then flows through the heat-radiating pipe of condenser, cooling down and changing into high-pressure low- temperature liquid. The liquid then flows through the dryer, which performs the functions of dehumidifying and buffering. The liquid then flows at a stable pressure and flow rate into the expansion valve, which performs the functions of throttling and pressure reduction. Finally, the liquid flows into the evaporator. Once entering the low-pressure environment, the refrigerant evaporates absorbing a great deal of heat.
•
The air inside the vehicle continuously flows through the evaporator, lowering the temperature inside the vehicle. The liquid refrigerant flows through the evaporator thus changes into low-pressure gas again. The gas is then drawn into the compressor again to perform the next cycle.
•
In the refrigeration system, the expansion valve is the member that controls the refrigerant flow into the evaporator. Should too much refrigerant flow into the evaporator, the evaporation would be difficult hence the cool gas flow would be insufficient. In this sense, the expansion valve is a regulating center. The compressor is the heart of the refrigeration system in that it is the power source for refrigerant cycle.

61
3.8.4 Refrigerant and refrigeration oil
Refrigerant：
•
Model: R134a；filling volume: 830±20gRefrigeration oil:
•
Model PAG56 (polyalkylente glycol).
•
Added volume of new vehicle: 120ml
•
Injection volume during component replacement: evaporator: 25ml Cooler: 15ml Hose: 20ml Pipe: 10ml
Notice: the air conditioning system shall meet with the items below
Refrigerant: it's only limited to HFC-134aFilling volume: 830±20gRefrigeration oil: PAG56Filling volume: 120ml

62
3.8.5 Circuit diagram of air-conditioning system
Compressor relay
Relay of fan of air- conditioning system
Relay of cooling fan
Air conditioning compressor
Clutch coil
Cooling fan
Fan of water tank
A/C switch
Air conditioner pressure switch
EMS (Engine management system)
Air conditioner temperature sensor
Power line
Windscreen wiper switch
Switch of roof evaporator
Speed-regulating resistor
Motor of roof evaporator
Speed-regulating resistor of air blower
Air blower
Bonding point -9
Bonding point -8
Bonding point -4
Bonding point -3
Bonding point -4

63
•
•
•
Get familiar with MZ40 light system characteristics and configuration.
•
Get familiar with MZ40 light system circuit reading and fault judgment skill. Preparations of field practice tools
•
One MZ40 vehicle with high configuration, one MZ40 maintenance manual, one special diagnostic instrument, two special high impedance ammeters for vehicle, four LED test lamps, several pins for circuit test, one roll of electrician tape, one set of normal disassembly tool, one set of vehicle interior disassembly tool, one rubber hammer, several pairs of gloves and cloth. Field practice item (operation duration 30 minute)
•
Test whether the light system is normal by operating the light system switch, your test result is_______. Before opening the front fog lamp, open__; before opening the rear fog lamp, open__. Open overtake lamp when the headlight is OFF, ____lamp will be on. Open overtake lamp when the headlight is ON, ____lamp and__lamp will be on at the same time.
3.9.1 Field practice on MZ40 light system
3.9 Field operation practice form of body electric
Relay of headlamp
Relay of width lamp
Relay of headlampCombination switch
Left front low-beam lamp
Right front low- beam lamp
Left front high- beam lamp
Right front high- beam lamp
Bonding point -3
Bonding point -2
Bonding point -1

64
•
•
•
Get familiar with MZ40 power window characteristics and configuration.
•
Get familiar with MZ40 power window circuit reading and fault judgment skill. Preparations of field practice tools
•
One MZ40 vehicle with high configuration, one MZ40 maintenance manual, one special diagnostic instrument for BAIC Weiwang, two special high impedance ammeters for vehicle, four LED test lamps, several pins for circuit test, one roll of electrician tape, one set of normal disassembly tool, one set of vehicle interior disassembly tool, one rubber hammer, several pairs of gloves and cloth. Field practice item (operation duration 30 minute)
•
Plug out left front door window switch plug; test whether the right front window switch can still control lifting of the right front window, your test result is______. Plug out right front door window switch plug; test whether the left front window switch can still control lifting of the right front window, your test result is______.
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Measure left front window ascending relay coil resistance as_____Ω, left front window descending relay coil resistance as_____Ω. Left front window motor resistance_____Ω.
3.9.2 Field practice of MZ40 power window
Control module of right front power window
Switch of right front power window
Switch of left front power window
Control module of left front power window
Motor for lifting left front power window
Bonding point -4
Bonding point -4

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Chapter IV transmission and chassis system

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4.1.1 Transmission model description and transmission parameter
4.1 MR510D05 transmission
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MZ40 vehicle LJ474 engine is equipped with MR510D05 manual mechanical five-speed transmission.
Maximum input torque
Transmission ratio of each gear
Gear ratio of the odometer
Gear 1
Gear 2
Gear 3
Gear 4
Gear 5
Reverse gear
110 N.m
4.101
2.304
1.675
1.227
1.00
4.722
17/5
Gear mode
4.1.2 Operation and maintenance of transmission
Oil drain hole
Use of the transmission oil
•
Lubricating oil number: 85W/90-GL- 4GB13895-92.
•
Oil to fill: 1.5L (dry type), 1.3L (wet type).
Kilometer
1?04
2?04
3?04
4?04
5?04
6?04
7?04
Month
6
12
18
24
30
36
42
Method
B
H
B
H
B
H
B
Regular maintenance cycle for the transmission
Replace transmission fluid at the initial maintenance, when the running-in period expires, and at the end of first 2500km.
Apply regular maintenance after the first time, the cycle depends on the readings on the odometer or number of month, if either reaches first.
Denotation of symbols: B: Change the transmission oil if necessary during the maintenance;
H: Change the transmission oil

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It’s sectional and easy to machine, with good stiffness, easy to disassemble, also with compact and reasonable structure
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The transmission has three shafts: input shaft, countershaft, and output shaft.
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The transmission adopts inertia synchronizers, which ensure the gear shifting is reliable, stable and flexible. The gear 1, 2 synchronizer is installed on the countershaft. The gear 3, 4 synchronizer and the gear 5 synchronizer are installed on the input shaft.
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The transmission is designed to have construction uniqueness, ensuring excellent power performance and fuel economy.
4.1.3 Construction features of transmission
High speed synchronizer
Input shaft
Reverse gear
Gear 5 synchronizer
Output shaft
Countershaft
Low speed synchronizer

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4.1.4 Power transmission principle of the transmission
1
2
R
5
4
3
Input shaft →Gear of first gear, countershaft →Low speed synchronizer →Countershaft → Drive gear, countershaft → Output shaft
Input shaft →Gear of second gear, countershaft →Low speed synchronizer →Countershaft → Drive gear, countershaft → Output shaft
Input shaft-high speed synchronizer–third gear of input shaft-countershaft-Drive gear, Countershaft - output shaft
Input shaft-high speed synchronizer–fouth gear of input shaft-countershaft-Drive gear, Countershaft - output shaft
Input shaft→Gear 5 synchronizer→output shaft
Input shaft →Idle gear of reverse gear →Low speed synchronizer →Countershaft →Drive gear, Countershaft →Output shaft

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4.2.1 Suspension system
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MZ40 vehicle adopts front Macpherson independent suspension and dependent rear suspension of longitudinally-arranged leaf springs, ensuring comfort while enhancing supportability.
•
Front Macpherson independent suspension is simple and , compact in constucture and fairly cheap in cost. The design and arrangement of sliding strut reduces the loss of camber angle due to lateral force and improves the operability and responsiveness of steering.
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Dependent rear suspension of longitudinally-arranged leaf springs simplifies construction and enhances supportability.
4.2 Chassis system

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Brake system of MZ40 adopts disc brakes for front wheels and drum brakes for rear wheels. The brake system has a vacuum booster and a load-sensing proportioning valve.
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Front wheel brake is sliding Caliper disc brake, adopts single piston and it’s ventilation brake.
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The rear brake is leading trailing shoe brake, work as common brake and parking brake, it has clearance self-regulating device.
•
The load sensing proportional valve equipped will ensure proper proportion of the front and rear wheel load during drive as well as the brake of front wheel before rear wheel during emergent brake. At the same time, in case of emergency braking, the load-sensing proportioning valve adjusts brake fluid pressure according to vehicle load and road resistance so that approximately ideal braking forces are applied to the brake pad of front wheel and the brake shoe lining of rear wheel. This can to some extent prevent wheel from slipping sideways and being locked, and reduce braking distance and improve braking effect.
4.2.2 Brake system

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Six-way valve
Load-sensing proportioning valve
Brake, left front
Right front brake
Brake, left rear
Right rear brake
Vacuum booster and master cylinder of brake
Brake system structure composition diagram
Master cylinder of brake
Six-way valve
Brake, left front
Right front brake
Load- sensing proportioning valve
Right rear brake
Brake, left rear

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•
MZ40 vehicles adopt rack and pinion mechanical steering system, it has a simple and compact structure, light weight, strong stiffness, sensitive steering, high reverse efficiency and it’s easy to install. It matches pretty well with Macpherson suspension.
4.2.3 Steering system

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•
MZ40 vehicle uses the rear axle as the drive axle. The drive axle consists mainly of the final drive and differential assembly, rear axle housing assembly, and axle shaft sub-assembly.
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The final drive is a single-stage drive of hypoid bevel gears. The differential has two symmetrically- arranged planetary bevel gears. The semi-floating axle shaft transmits power from the final drive to the drive wheel.
4.2.4 Transmission system

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Tyre pressure: 220 bar of front wheel, 280 bar of rear wheel
4.2.5 Tire specification
Aluminum hub (high configuration)
Iron hub (low configuration)
175 / 70 R 14 LT
Represent tire fracture width (mm)
Represent tire fracture flat rati
Represent radial structure
Represent nominal diameter of rim (inch)
Represent light load radial tire
Tire model：175/70R14LTBrand: Beijing CapitalDouble Star Dongfeng
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175/70R14 means that the tire is 175mm wide, 70 means that the tire side wall height is 70% of tire width, 14 means that the tire rim is 14 inch, LT represents light load radial tire; the tire's highest speed is 190KM/h, highest load 475KG, peaking inflating pressure 300KPa

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4.2.6 Tire positioning parameter
Wheel alignment parameters of MZ40 (under no load) Camber angle: 45`±30` Caster angle: 2°45`±45Tie-in: 0`～12`(0～2.5mm) Kingpin inclination: 8°54`±45` Slip sideways of front wheel m/km: 5Rotation angles of front wheels: 37°±2°outer wheel; 32°±2°inner wheel
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Function of the toe-in of front wheel: Eliminating the tendency of front wheel outward rolling caused by outward tipping. Reducing wear of tyre.
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Function of camber angle: prevent tire inclination; reduce force of small bearing outside the hub and prevent outward skid of tire; facilitate contact with arch road.
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Function of kingpin inclination: automatically return the front wheel; make steering operation convenient; reduce impact force on the steering disc.
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Function of caster angle: ensure linear drive of vehicle; properly increase the cast angle to make the steering easier; exert very good damping on the steering shock; to proper increase the cast angle is an effective method to return the tire.
Purpose of Four-wheel alignment:
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Wheel self-aligning, guarantee the vehicle's straight line driving, easy steering, less tire and components wear.
Camber
Kingpin inclination

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