Chery A series. Manual - part 46

 

 

the ignition switch again to re-operate the 
fuel pump in order to verify that the fuel 
pressure can be established. 

No 

Proceed to Step 16. 

Yes 

Replace the fuel pressure 

regulator 

15 

Open the fuel manometer valve and 
clamp the fuel return pipe with the fuel 
tube clamp to stop the fuel return in order 
to verify that the fuel pressure can be 
established quickly. 

No 

Repair or replace the fuel 

injector or fuel pipe 

Yes 

Repair or replace the fuel 

air inlet pipe 

16 

Verify that the fuel inlet pipe has any 
leakage or blockage. 

No 

Replace the fuel pump 

Yes 

Repair or replace the fuel 

return pipe 

17 

Verify that the fuel return pipe has any 
leakage or bending. 

No 

Replace the fuel pressure 

regulator 

Yes Clean 

18 

Verify that the sensing holes of the 
pressure and temperature sensor of air 
intake manifold have any blockages. 

No 

Proceed to next step. 

Yes 

Proceed to next step. 

19 

Run the engine at idle speed. When the 
coolant temperature reaches the 
temperature of activating the close- loop 
control, verify that oxygen sensor 
functions normally. (Fluctuating within 
the range of 0-1V) 

No 

Inspect the oxygen 

sensor and the wiring 

harness 

Yes 

Fix the leakage 

 

20 

Verify that the engine air intake system 
has any leakage. 

No 

Proceed to next step. 

Yes 

Proceed to next step. 

21 

Verify that the pressure of engine 
cylinder is normal. 

No 

Fix the malfunction 

Yes 

Replace the ECU. 

22 

Run the engine at idle speed until the 
coolant temperature reaches its normal 
range in order to verify that the ignition 
advance angle is normal. 

No 

Inspect other items 

 

 

G-73

 

7) Unstable idle speed during engine warm-up 

Yes 

Fix the indicated 

malfunction 

1 

Turn the ignition switch to “ON” position. 
Inspect with the diagnostic tester to see 
whether there is any malfunction information 
record. 

No 

Proceed to next step.

Yes 

Proceed to next step.

2 

Verify that the air filter is free of any blockage.

No Replace 

Yes 

Proceed to next step.

3 

Run the engine at idle speed. Verify that the air 
intake manifold pressure is maintained 
between 35-65 kPa during warm-up. 

No 

Fix the leakage of air 

intake system 

Yes 

Proceed to next step.

4 

Shut down the engine. Turn on the ignition 
switch and connect the adaptor between ECU 
and the wiring harness. Verify that the voltages 
at air intake temperature sensor, water 
temperature sensor, and ECU’s pins of 32# and 
33# (used as sensor power supply of 4.5-5V) 
are normal. 

No Service 

Yes 

Proceed to next step.

5 

Disconnect the connector of idle speed actuator 
before ending the engine warm-up and verify 
that the engine speed is changed. 

No 

Replace the idle 

speed actuator 

Yes 

Proceed to next step.

6 

Verify that the coolant temperature sensor is 
normal. 

No Replace 

Yes 

Replace the ECU. 

7 

Run the engine at idle speed until the coolant 
temperature reaches its normal range in order 
to verify that the ignition advance angle is 
normal. 

No 

Inspect other items 

 
 

 

 

 

 

 

 

 

 

 

 

 

G-74

 

8) Unstable idle speed or stall with load (A/C and etc.) 

Yes 

Fix the indicated 

malfunction 

1 

Turn the ignition switch to “ON” position. 
Inspect with the diagnostic tester to see 
whether there is any malfunction 
information record. 

No 

Proceed to next step. 

Yes 

Proceed to next step. 

2 

Turn on the A/C switch and connect the 
adaptor between ECU and the wiring 
harness. Measure and see whether the 
ECU’s A/C switch and pressure signal 
have any signal input. 

No 

Overhaul the A/C 

circuit. 

Yes 

Proceed to next step. 

3 

Verify that the pressure of A/C system, 
the magnetic clutch of compressor and 
A/C pump are normal. 

No 

Repair or replace. 

Yes 

Proceed to next step. 

4 

Turn the ignition switch to “ON” position. 
Verify that the voltages at ECU’s pins of 
65#, 64#, 67#, and 66# (output connected 
to idle actuator) are normal. 

No 

Inspect the control 

circuit. 

Yes 

Repair or replace the 

step motor. 

5 

Remove the step motor to verify that it is 
jammed or runs unfreely. 

No 

Proceed to next step. 

Yes 

Replace the ECU. 

6 

Start up the engine and turn on the A/C. 
Inspect with the diagnostic tester through 
the step amount of step motor to see 
whether the idle actuator functions 
normally. (The normal step amount will 
be provided otherwise) 

No 

Replace the idle 

actuator. 

 

 

 

 

 

 

 

 

 

 

 

 

 

G-75

 

9) Unstable idle speed after engine warm-up 

Yes 

Fix the indicated 

malfunction. 

1 

Turn the ignition switch to “ON” position. 
Inspect with the diagnostic tester to see 
whether there is any malfunction 
information record. 

No 

Proceed to next step. 

Yes 

Proceed to next step. 

2 

Turn the ignition switch to “ON” position 
and connect the adaptor between ECU and 
the wiring harness. Verify that the 
voltages at following ECU’s pins such as 
absolute pressure sensor output of air 
intake manifold, air intake temperature 
sensor output, coolant temperature sensor 
output, oxygen sensor output and ECU’s 
output voltage connected to idle actuator’s 
pin are normal. 

No 

Repair or replace the 

wiring harness and 

relevant parts. 

Yes 

Proceed to next step. 

3 

Shut down the engine and verify that the 
air filter is free of any blockage. 

No Replace 

Yes 

Proceed to next step. 

4 

Verify that the air intake manifold 
pressure is maintained between 35-65 kPa 
at idle speed. 

No 

Fix the leakage of air 

intake system 

Yes 

Proceed to next step. 

5 

Connect the fuel manometer valve (the 
connecting points will depend on the types 
of car models). Short the 30# and 87# pins 
of the fuel pump relay to operate the fuel 
pump in order to verify that the fuel 
pressure is maintained at about 350kPa. 

No 

Proceed to Step 9 

Yes 

Proceed to Step 8 

6 

Provide a voltage supply of 12V with 
special connector between the battery and 
the fuel injector, and verify that the fuel 
injector is functioning normally. 

No 

Proceed to next step. 

Yes Replace 

7 

After washing and cleaning the fuel 
injector, inspect again to see whether it 
can function normally. 

No 

Replace the fuel 

injector. 

Yes 

Replace the fuel. 

8 

Verify that the fuel is deteriorated or 
contaminated with water. 

No 

Proceed to Step 14. 

Yes 

Proceed to next step. 

9 

Verify that the fuel pressure is lower than 
350kPa. 

No 

Proceed to Step 13. 

Yes 

Proceed to next step. 

10 

Turn off the fuel manometer valve. 
Connect the ignition switch again to 
re-operate the fuel pump in order to verify 
that the fuel pressure can be established. 

No 

Proceed to Step 12. 

11 

Turn on the fuel manometer valve and 
clamp the fuel return pipe with the fuel 

Yes 

Replace the fuel 

pressure regulator. 

 

G-76