Chery A11. Manual - part 108

 

 

 

 

 

 

 

 

Part  MOT multi-port electric fuel injection engine system 

 

 

SQR480EC electric fuel injection system 

I. System 

description 

Electric fuel injection system is a complete functions system and mainly consists of fuel 

system, air system and electric control system.  It also includes ignition control and 

exhaust control functions etc.   

 

Fuel system 

Fuel passes through fuel tank built-in oil pump to fuel filter, and is pressed to oil rail after 

filtering, then sprayed into cylinder via fuel injector, and then returns to fuel tank through fuel 

pressure adjuster, which can maintain constant fuel pressure. Fuel injector locates at the air 

intake port of each cylinder and spray fuel into cylinder. 

 

Air system   

Air system includes air intake system air cleaner, air pressure sensor, temperature sensor, 

throttle valve body, air intake hose and manifold, and idle adjuster valve and idle adjuster 

screw for idle adjusting. 

 

Electric Control System   

Consists of sensor, ECU and actuator, including ECU, air intake temperature and pressure 

sensor, water temperature sensor, throttle valve position sensor, oxygen sensor, electric oil 

pump, fuel injector, ignition coi land throttle valve body etc. 

 

13  Oil pressure adjuster 

14  Oxygen sensor 

15  3-way catalyst converter 

Engine coolant temperature sensor (water 

 temperature sensor) 

17    Crankshaft position RPM sensor 

18  ECU 

19  Battery 

20  Electric fuel injector 

21  Pressure switch 

22  Ignition switch 

23  A/C compressor 

 

1  Fuel Vapor Tank (carbon canister) 

Oil pump 

Fuel tank 

Engine 

Fuel rail 

Air Intake Temperature And Pressure Sensor 

Air cleaner 

Idle step motor 

Throttle position sensor 

Throttle valve body 

Spark Plug  12  Ignition coil 

 

II. Operation 

SQR480EC electric fuel injection system controls ignition, fuel injection, idle ect. upon 

engine speed signal, air intake pressure, throttle position signal, air temperature signal, 

oxygen sensor signal and coolant temperature signal.  The system utilize an advanced 

control strategy, and selected components and a complete set of strict production process, 

and is an electric fuel injection system featuring intelligence and stability, meets the strict 

technological demands of car manufacturer with the exhaust meeting the Euro II standard.   

The fuel system offers a 2.5 Bar fuel supply pressure. 

 

2.1 electric control system 

2.1.1 ECU 

Parameter

Unit Minimum 

Maximum

Operating 

voltage 

Volt 6.5 16 

Operating 

current 

Ampere 0.01 

0.1 

Operating 

temperatu

re 

Centigrade

-40 85 

Humidity

%RH 20  85 

Vibrating 

frequency

HZ … 1000 

 ECU operation ambient temperature range is -40℃---+85℃, therefore, before baking 

varnish for the automobile body, it should be removed first, and the temperature should be 

under strict control to avoid ECU being damaged. 

 

2. ECU damage has a low damage probability (damage ratio less than 1/1000 after 100000 

KM mileage) and do not suspect the ECU damage. Even ECU damage is suspected, do not 

attempt to disassemble it (replace the internal core) because a defective ECU can not be 

repaired. 

 

EI system wiring harness 

For MPI-ECU wiring harness assembly (multi-port fuel injection---ECU wiring harness), 

see illustration. 

Engine wiring harness 

See illustration. 

Water Temperature Sensor 

Sensor has 2 leads, one is signal lead (pin B10) and the other is ground lead (pin B23)   

 

Water 

Temperature 

Ohm

 

 

●Measuring Method 

a ohmmeter method 

Measure resistance with an ohmmeter, and determine if water temperature sensor operates 

upon measured engine coolant temperature and below diagram. Remove coolant 

temperature sensor, immerse into water and heat water. The sensor has different resistance 

at corresponding temperature. 

Water Temperature Sensor Resistance Specification 

Temperature(℃)

Resistance(Ω)

Temp.(℃)

Resistance(Ω) Temp.(℃)

Resistance(

-40 100865 

25 

2795 

90 

241.8

-35 72437 

30 

2240 

95 

207.1

-30 52594 

35 

1806 

100 

178.0

-25 38583 

40 

1465 

105 

153.6

-20 28582 

45 

1195 

110 

133.1

-15 21317 

50 

980 

115 

115.7

-10 16120 

55 

809 

120 

100.9

-5 12261 

60 

671 

125 

88.3

0 9399 

65 

559 

130 

77.5

5 7263 

70 

469 

135 

68.3

10 5658 

75 

395 

140 

60.3

15 4441 

80 

334 

145 

53.4

20 3511 

85 

283 

150 

47.5

b  voltmeter method 

  Install the sensor on the motor, and crank engine. Connect sensor signal lead to 

voltmeter, there are different    voltage drop at different temperature. 

 

Oxygen sensor 

Oxygen sensor is installed on exhaust pipe and accurately regulate excess air co-efficiency . 

Oxygen sensor has 4 leads: C. voltage lead (pin A16) B. signal lead (pin B1)   

A. signal ground (pin B23)      D heater ground (pin B16) 

                                                                                       

PIN Function 

C Sensor 

voltage lead 

B Sensor 

signal 

output 

A Signal 

ground 

D Heater 

ground 

Oxygen sensor heater resistance impedance specification table                      

when temperature is 23℃, impedance is 

13.2+/-10%

 

Resistance Heat Co-efficiency of 

impedance 

(23-800℃) (ppm/℃) 

1150