Chery A11. Manual — part 167

Maintenance Manual for Chery·Windcloud

Marelli EFI System

with fuel return interceptor to ensure no fuel
return, and check if fuel pressure is formed
rapidly.

No Repair/

replace

injector or fuel pipe

Yes

Repair or replace fuel
inlet pipe

14

Check if leakage or clogging occurs in fuel inlet
pipe

No

Replace fuel pump

Yes

Repair or replace fuel
return pipe

15

Check if fuel return pipe is blocked up or bent.

No Replace

pressure

regulator

Yes

Go to next step

16

Check if data of intake manifold absolute
pressure and intake air temperature sensor is
normal.

No Replace

sensor

Yes

Go to next step

17

Check if spark plug, high voltage line and
ignition coil are in good condition.

No

Replace or adjust

Yes Check

air

conditioning system

18

Check if caused by air conditioning system.

No Replace

ECU

15). Air conditioning system failure

Yes

Go to next step

1

Check if there is enough refrigerant in system,
and if air conditioning belt, air conditioning
clutch and pressure switch are working in good
condition.

No Troubleshooting

Yes Eliminate

failure

displayed

2

Make engine run at idle speed, and switch on air
conditioning switch. Check with scanner to see
if failure of air-conditioning thermal resistor
occurs.

No

Go to next step

Yes

Go to next step

3

Turn on air conditioning switch, connect
commutator between ECU and wire harness,
and then measure to see if there is signal input
on air conditioning switch, air conditioning
pressure of ECU.

No

Check wire harness

Yes

Replace bulb or
repair wire harness

4

In case low-level control is adopted, check if
air-conditionor still works when it is OFF.

No

Go to next step

Yes

Repair

air

conditioning relay
and wire harness

5

Check if there is low-level output at ground
terminal of pull-up coil of ECU air conditioning
relay.

No Replace

ECU

56

Maintenance Manual for Chery·Windcloud

Marelli EFI System

8. System Maintenance Safety Precautions

1). Diagnostic maintenance safety precautions for EFI system
(1). Controller dismounting requirement
Controller shall be dismounted before electric welding or stoving varnish;
When dismounting controller, ignition switch shall be pulled to OFF so as to avoid damage;
Do not pull out power line from accumulator when engine is in operation or electric system is
in use (with surge voltage);
Do not use heavy current of charger to start engine;
Caution: the ambient temperature of controller shall not exceed 80°

(2). Cleaning requirement: The following regulations shall be observed in a serious manner
before operating on fuel supply system and fuel injection system:
Dismounted parts shall be placed at clean site and well-covered with silk as appropriate
instead of fiber-falling cloth;
(3). Various wire harnesses and wire harness of scanner shall be unplugged and plugged after
ignition switch is OFF;
When measuring voltage or grounding on electronic control system, correct connection shall
be ensured;
Diagnostic and self-learning information stored may be lost due to power line pulled down or
controller connector of wire harness unplugged from accumulator.
(4). Precautions on fuel supply system maintenance
When disassembling and assembling fuel pump on the fuel tank filled or partly filled with
fuel, pay attention to the following:
Before operation, device well enough to absorb leaking gasoline shall be installed
neighboring fuel tank opening.
Avoid direct contact of skin with gasoline.
Before loosening a connection, make sure to clean thoroughly the part and its surroundings;
In order to avoid fuel splash of loosen part, duster cloth shall be laid on the surroundings of
the connection;
If maintenance is not carried out immediately on unclosed part, the said part shall be covered
or sealed carefully;
Fittings shall be taken out from package prior to assembling, no fittings without package are
allowed to be used;
When installing injector, make sure not to damage O- ring; in order to facilitate assembling,
apply small quantity of lubrication oil on the said ring;
Do not use compressed air and do not move vehicle as far as possible after system is opened.
2) Safety measures
In order to avoid personnel injury as well as fuel injection and ignition device damage, pay
attention to the following:
(1). If engine is in operation or at starting rotating speed, do not touch or unplug ignition wire
harness;
If engine is to be droven by starting motor instead of starting itself, for example on occasion
of compression pressure examination, wire harness plugs shall be pulled out from Hall sensor
and crankshaft position sensor.

57

Maintenance Manual for Chery·Windcloud

Marelli EFI System

Caution: the ECU plug of A-series engine is liable to have problem of interior looseness,
in case such problem occurs while line, sensors and control unit are all normal, ECU
wire harness shall be replaced or ECU plug shall be disposed of.

58

Maintenance Manual for Chery·Windcloud

MOTOROLA EFI System

1

Chapter One: Operating Principle for EFI
Control and Execute Components

1. Intake Pressure and Intake Air
Temperature Sensor

MOTOROLA EFI system adopts air

measurement method of velocity and density to

measure the air capacity entering engine so as

to control fuel injection pulse width further

accurately control engine power output.

Pressure-sensitive element inside intake
pressure sensor detects pressure signal on

intake manifold via sensing hole connecting

intake manifold, within which is a

pressure-sensitive element, the resistance value

varies with the changing pressure, after

conversion of this signal, it will become an

important parameter for the control of engine

performance.

Intake air temperature sensing element is a

resistor of negative temperature coefficient

(NTC), which is similar to water temperature

sensor with resistance value decreasing with

the increasing of intake air temperature. And

engine ECU monitors the variation of intake air

temperature via a comparison circuit inside.

Failure diagnosis:

Short circuit occurs on the sensor line circuit;

Open circuit occurs on the sensor line circuit;

Sensor detects intake pressure to be over upper

limit;

Sensor detects intake pressure to be over lower

limit;

Installation: to be installed on pressurizer.

Troubleshooting: mainly check if there is

short circuit or open circuit on the connection

between 4 lines on senosr and ECU.

If sensor’s sensing hole is pluged up.

If there is short circuit, open circuit or

grounding between sensor wire harnesses.

Manifold absolute pressure /intake air temperature sensor

Intake temperature /
pressure sensor

Circuit diagram of manifold absolute pressure and intake
air temperature sensor

Pins: 1# connects with standard 5V power

source (connecting ECU B22#);

2# outputs pressure signal (connecting

ECU B19#);

3# sensor ground (connecting ECU

23#);

4# outputs temperature signal

(connecting ECU B18#).

Side view of intake pressure and intake air temperature

sensor