53 

 

Canister valve failure 

Oxygen sensor failure 

Engine bracket cracked 

Low fuel pressure 

Intake temperature sensor failure 

Exhaust system blocked 

Injector failure 

Voltage abnormal 

Intake pipe leak 

Individual cylinder fails to work 

Electric controlling system failure 

Idle speed control valve or stepping motor failure 

Idle speed by-pass pipe blocked 

Improper throttle position sensor adjustment 

Idle speed unstable 

Clean 

Check 

Check 

Clean and replace 

Replace 

Replace 

Replace 

Replace 

Replace 

Check and replace 

Check 

Check 

Clean and replace 

Adjust and replace 

Low 

Cracked 

Fail 

Abnormal 

Abnormal 

Abnormal 

Blocked 

Abnormal 

Abnormal 

Abnormal 

Improper adjusted 

Blocked 

Fails to work 

Leak 

Normal 

Normal 

Normal 

Normal 

Normal 

Normal 

Normal 

Normal 

Normal 

Normal 

Normal 

Normal 

Normal 

 
 

 

 

54 

 

No. 031 Non-idle speed   

Malfunction Cause 

Solution 

Idle speed air pipe blocked 

Check throttle and idle speed air pipe, whether they are blocked. Clean 
them if there is too much carbon deposit to ensure free-flowing intake. 

Ilde speed stepping motor 
malfunction 

Check idle speed stepping motor, whether it operates normally and flexibly. 
Clean it if there is too much carbon deposit. Replace motor when 
necessary. 

Loose throttle pedal and check throttle cable condition, adjust it if the 
clearance is improper. 

Improper throttle cable or 
thorttle position sensor 
adjustment 

When throttle is closed totally, inspect throttle position sensor idle speed 
switch, by Geely special decoder, whether it operates normally. Adjust or 
replace it when necessary. 

Electric controlling system 
malfunction 

Connect Geely special decoder to check whether there is malfunction code. 
And inspect again if it shows malfunction code. Then check relevant 
component and circuit according to the indication of malfunction code. 

Cooling fluid temperature 
sensor malfunction 

Check cooling fluid temperature sensor. In different temperatures, the 
resistance of coolant temperature sensor shall vary according to regulated 
standard. Otherwise, replace it. 

Indicidual cylinder fails to 
work 

Check operating condition of each cylinder, whether individual cylinder 
operates abnormally, particularly inspect the spark plug, spark wire and 
cylinder pressure etc. Maintain or replace relating parts when malfunction 
cause was found. 

Engine voltage abnormal 

Check running engine, whether the output voltage of generator is in normal 
value. If it is abnormal and results unstable idle speed, then check 
generator and relating circuit and parts. Maintain or replace them when 
necessary. 

Intake system leaking 

According to idle speed operating principle, vacuum pipe leaking will result 
non-idle speed. Shall replace vacuum pipe. 

Incorrect engine valve 
timing 

Timing belt loose and cause gear malposition, as well as similar condition 
with non-idle speed. Shall adjust ignition timing. 

Circuit malfunction 

Part of idle speed controlling circuit is ageing or affected by water, may 
result non-idle speed. Shall maintain circuit. 

Non-idle speed, 
engine shut-off 
when pressing 
throttle pedal 

Engine ECU malfunction 

Pull out ECU engine connector, measure the resistance between each 
terminal by multimeter, whether the value is corresponding to technical 
requirements. Replace engine ECU when abnormal. 

 

 
 

 

 

55 

 

Engine ECU failure 

Circuit failure 

Incorrect engine valve timing 

Intake system leaking 

Engine voltage abnormal 

Indicidual cylinder fails to work 

Cooling fluid temperature sensor failure 

Electric controlling system failure 

Improper throttle cable or thorttle position sensor adjustment

Ilde speed stepping motor failure 

Idle speed air pipe blocked 

Non-idle speed 

Check 

Check 

Clean and replace 

Replace 

Replace 

Check and adjust 

Check 

Check 

Check 

Clean and replace 

Clean 

Leak 

Error 

Fails to work 

Abnormal 

Abnormal 

Abnormal 

Abnormal 

Abnormal 

Abnormal 

Abnormal 

Blocked 

Normal 

Normal 

Normal 

Normal 

Normal 

Normal 

Normal 

Normal 

Normal 

Normal 

 
 

 

 

56 

 

No. 032 Idle speed over normal value   

Malfunction Cause 

Solution 

Improper throttle cable or throttle position 
sensor adjustment 

Loose throttle pedal and check throttle cable condition. 
Adjust it when the clearance is improper. 

Throttle contains too much carbon deposit, 
sc. it is stuck, which results the throttle fails 
to close normally. 

Check throttle, if there is too much carbon deposit, which 
results throttle fails to close as normal, then shall clean it.

Idle speed stepping motor malfunction 

Check idle speed stepping motor, whether it operates 
flexibly. If it is stuck, caused by carbon deposit, and then 
shall clean it. Replace stepping motor when necessary. 

Intake system leaking 

Intake pipe leaking, result incorrect decision to air flow 
rate on ECU, and causes improper control, which leads 
to over idle speed. Check leaking position, particularly 
the intake manifold gasket, fuel injector seal ring, 
vacuum pipe and connector etc. 

Electric controlling system malfunction 

Connect Geely special decoder to check whether there 
is malfunction code. And inspect again if it shows 
malfunction code. Then check relevant component and 
circuit according to the indication of malfunction code. 

Cooling fluid temperature sensor 

malfunction 

Check water temperature sensor, whether it can send 
temperature signal to ECU correctly. In normal condition, 
the coolant temperature is applied to adjust fuel injecting 
quantity, sc. mixture gas viscosity. In low temperature, 
ECU controls injector to inject more fuel to increase 
mixture gas viscosity, as well as idle speed. Check water 
temperature sensor, if it fails to measure temperature as 
normal. In different temperatures, the resistance of 
cooling temperature sensor shall vary according to 
regulated standard. Otherwise, replace coolant 
temperature sensor. 

Intake pressure sensor malfunction 

Check intake manifold pressure temperature sensor, 
replace it when abnormal. 

Oxygen sensor malfunction 

Measure oxygen sensor, if the voltage is low, beneath 
0.5V, then will cause incorrect ECU order, which results 
mixture gas viscosity increase, as well as idle speed. 
Replace oxygen sensor when necessary. 

Idle speed over 
normal value 

Engine ECU malfunction 

Pull out engine ECU pin and measure the resistance 
between each terminal of ECU, whether the value is 
accordance with technical requirements. Replace engine 
ECU when abnormal.