Maintenance Manual for J2 Sedan
Electronic Control System
of Engine
221
Fault code: P0501 “the vehicle speed signal is unreasonable”
S/N
Step
Check result
Subsequent step
1
Connect the diagnosis device and adapter, and turn the ignition switch
to OFF position.
Next step
Yes
Check and repair
ABS system
2
For the car with ABS system, please check if the ABS system has any
fault code.
No
Next step
Yes
Next step
3
Check if the finger of speedometer operates normally.
No
Check and repair
the instrument
circuit
Yes
Next step
4
Check if the vehicle speed sensor operates normally.
No
Replace the
vehicle speed
sensor
Yes
Repair or replace
the harness
4
Check if the circuit connecting to vehicle speed sensor signal wire to
Pin 57# of ECU is open or short to power source or ground.
No
Diagnosis help
Fault code: P0506 “the idle speed is the lower than the target idle speed”
S/N
Step
Check result
Subsequent step
1
Connect the diagnosis device and adapter, and turn the ignition switch
to OFF position.
Next step
Yes
Next step
2
Check if the adjusting screw, cable and condition of throttle are good.
No
Do the necessary
repair and
maintenance
Yes
Next step
3
Check if the working condition of idle regulator is good.
No
Do the necessary
repair and
maintenance
Yes
Do the necessary
check and repair
4
A. Check if the pressure of fuel supply system is too low.
B. Check if the fuel injector is blocked.
C. Check if the system exhaust line is blocked.
No
Diagnosis help
Fault code: P0507 “the idle speed is the higher than the target idle speed”
S/N
Step
Check result
Subsequent step
1
Connect the diagnosis device and adapter, and turn the ignition switch
to OFF position.
Next step
Yes
Next step
2
Check if the adjusting screw, cable and condition of throttle are good.
No
Do the necessary
repair and
maintenance
