Chery A11. Manual - part 169

 

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Chery A11. Manual - part 169

 

 

 

Maintenance Manual for Chery·Windcloud   

MOTOROLA EFI System

 

 

6

6. Electronic Control Unit (ECU) 
Purpose:   
With microprocessor as core composition, 
ECU has a sensor signal input interface, also, 
it is an electric control engine control center 
for actuator drive circuit, which receives and 
processes engine condition signals inputed by 
sensors, and sends out control signal to 
actuators so as to make the engine work as 
per scheduled program and achieve optimum 
condition of engine as well as ensure 
favorable power, fuel consumption and 
emission.  
 
 
 
Normal operation voltage: 9-16V 
 
 
Composition:  
it has shielded casing and 
printed circuit board, which integrates lots of 
electronic control units for the control of EFI 
system.  
 
 
Installation:  to be fixed by the support of 
bracket under pilot trench of front windshield. 
Pay attention to waterproofing.   

 

   

 

 

 

ECU 

Functions: 

 

Multipoint group injection 
Controlling ignition 
Idle speed control 
Knocking control 
Providing sensors with power supply: 
5V/100mA 
λ

closed-loop control with self-adaptation 

Controlling carbon canister control valve 
Air conditioning switch 
Engine-failure indication lamp 
Engine speed signal output 
Failure self-diagnosis with flash code 
function 
Accepting engine load signal 

 

Troubleshooting: due to the fact that ECU 
(electric control unit) has low failure rate, so 
generally it is not advisable to replace ECU for 
troubleshooting on any problem. Failure of 
components such as periphery circuit and 
sensors shall be checked and solved firstly. Do 
not replace ECU until all periphery components 
are confirmed to be fault-free. 

 

 

 

Maintenance Manual for Chery·Windcloud   

MOTOROLA EFI System

 

3. ECU Pins Definition:   

 

   

 

 
                                                                               

    B

 

     

Ground 

Ignition coil 2 

Air 

conditioning 

pressure 

switch 

Injector 3 

Rotation 

speed 

output 

Fuel

pump 

control

Radiator fan

Ground

Crankshaft 

position 

sensor positive

Vehicle 

speed 

sensor 

Crankshaft 

position sensor 

signal negative

Serial 

communication 

interface 

Bootstrap 

LPT 

Standard 

5V power

output 

Main 

power

Sensor 

ground

Idle stepper

motor 1B

Idle stepper

motor 1A

Compressor relay 

Ground

Condensor 

relay

Idle stepper

motor 2A

Idle stepper

motor 2B

Intake 

pressure

Ignition coil 1 

Injector 1 

Injector 4 

Injector 2 

Throttle 

position sensor 

Intake air

temperature

Air 

conditioning 

temperature 

sensor input

Water 

temperature 

sensor 

Oxygen 

sensor 

signal 

 

7

Maintenance Manual for Chery·Windcloud M

OTOROLA EFI System

 

7. Electric Fuel Pump 

 

Purpose:  to carry fuel from fuel tank to 

engine at a certain pressure and flow rate 

(different in systems). 

 

 
 
 
 
Composition and principle:
 electric fuel 

pump is coaxially installed with pump motor 

in the same casing. It is constituted by direct 

current motor, vane pump and end cover 

(integrating check valve, decompression 

valve and anti-electromagnetism 

interference component). The maximum 

pressure of electric fuel pump outlet is 

determined by decompression valve between 

450-650kPa, while the pressure of entire 

fuel system varies with manifold pressure. 

The difference between system pressure and 

manifold pressure is determined by fuel 

pressure adjuster, for MOTOROLA EFI 
system it is 250kPa in general.   

 
 

Caution: if fuel tank is in longstanding fuel 

starvation or fuel shortage, fuel pump will 

suffer from bad lubrication, which results in 

fuel pump cementing, especially for engines 

using CNG and LPG.   

 

Fuel temperature has fairly big impact on 

fuel pump performance, in case of 

longstanding operation under high 

temperature condition, when fuel 

temperature is higher than a certain value, 

the pressure of fuel pump drops dramatically, 

in this case, if engine fails to start when 

heating vehicle, please check carefully 

whether the high temperature performance 

of fuel pump is out of condition. 

 

 
 
 
 
 

 

Electric fuel pump 

 

Main power

Fuel pump relay

Fuel pump

 

Circuit diagram of electric fuel pump 

Pins: electric fuel pump has 2 pins, which 

connecting with fuel pump relay. “+” and 

“-” are marked on the fuel pump housing 

beside both of the 2 pins, which indicates 

connecting with anode and cathode 

respectively.  

ECU A21# pin controls fuel pump relay.   

 

Troubleshooting:  generally the failure of 

fuel pump appears as insufficient fuel 

pressure or no pumping-out of fuel. In case 

of troubleshooting, system fuel pressure 

shall be checked to see if it is within the 

scope of specified value and if pipeline is 

leaking.  

In addition,fuel tank’s positive pressure and 

negative pressure will have impact on fuel 

system.  

 

8

 

Maintenance Manual for Chery·Windcloud 

MOTOROLA EFI System

 

8. Electromagnetic Injector

 

Purpose:  according to ECU instruction, 

injector ejects fuel within the stipulated time, 

by which means providing engine wtih fuel 

and atomising it.   

 
Composition and principle: ECU sends out 

electric impulse to injector coil, forming 

magnetic field force. When the magnetic 

field force increases well enough to 

overcome resultant force of retracing spring 

pressure, pin valve gravity and friction, pin 

valve starts to lift, and the fuel injection 

begins. The maximum lift range of pin valve 

shall not exceed 0.1mm. In case fuel 

injection impulse is cut-off, the pressure of 

retracing spring enables pin valve to switch 

off again.   

 

Installation hints: a certain injector shall 

apply to a certain pin without mixing use.   

In order to facilitate installation, it is 

recommended to apply uncontaminated 

silicon-free engine oil to the surface of 

upper O-ring connecting with fuel 

distributing pipe. Be careful not to let engine 

oil contaminate interior or squirt hole of 

injector.  

 Install injector into injector seat in the 

direction perpendicular to the seat, and then 

fix the injector on it with clamp. 

 

 
 

Caution:  for long-term idle vehicle, 

gasoline cementation in injector results in 

failure of normal startup of vehicle after 

long-term idling. In this case please check 

carefully to see if the injector cements.   

 

Failure diagnosis: EFI system of A11 does 

not apply failure diagnosis to injector itself, 

but to injector driver stage. When the driver 

stage of injector is in short circuit or excess 

load status to accumulator, in short circuit 

and open circuit status to ground, the failure 

mark is set. At this point, shut down oxygen 

sensor closed-loop control and its 

self-learning precontrol, the last 

self-learning data is valid. After 

troubleshooting, failure mark restores. 

 

Working pressure: 350 kPa 

 

Injector resistance: 11-16

Ω 

 

Electromagnetic injector figure 

 

Main power

Injector set 

Circuit diagram of electromagnetic injector 

 

Pins: each injector has 2 pins. Of which, the 

one marked with positive sign beside 

housing shall be connected with 87# pin of 

fuel pump relay output terminal; the other 

shall be connected with A9#, A2#, A10# or 

A1# pin of ECU respectively. 

 

Troubleshooting: generally injection 

nozzle’s non-smooth fuel injection and 

defect atomization is caused by long-term 

application of engine. To solve this 

problem, periodical cleaning of injection 

nozzle is required.   

Short circuit, open circuit in interior coil of 

injection nozzle may also result in fuel 

injection system failure.   

Check to see if there is short circuit or open 

circuit in system line.   

Due to long-term usage of nonconforming 

fuel, the said fuel cements on squirt hole of 

injection nozzle, which is liable to cause 

failure of idle speed unsteadiness.   

 

9

 

 

 

 

 

 

 

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