Chery A series. Instruction - page 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