149 

Yes 

Repair or replace 
harness 

4 

Check lines between sensor signal line and 59# pin of ECU are opened or 
shorted to power source or ground. 

No Diagnosis 

help 

No.100 Malfunction code: P0506 "idling speed lower than target speed 

value"  

Serial No.  Operation steps 

Results   

Follow-ups   

1 

Switch on diagnosis instrument and commutator, and place ignition switch 
to “OFF”. 

 Next 

step 

Yes Next 

step 

2 

Check adjusting screw, throttle dragline and condition of throttle work 
normally.  

No 

Repair and 
maintain as 
necessary  

Yes Next 

step 

3 

Check idling speed governor works normally.   

No 

Repair and 
maintain as 
necessary 

Yes 

Repair as 
necessary 

4 

A. Check pressure of oil supply system is too low;   
B. Check oil injector is blocked;   
C. Check the system is well exhausted.   

No Diagnosis 

help 

No.101 Malfunction code: P0507 "idling speed higher than target speed 

value"  

Serial No.  Operation steps 

Results   

Follow-ups   

1 

Switch on diagnosis instrument and commutator, and place ignition 
switch to “OFF”. 

 Next 

step 

Yes Next 

step 

2 

Check adjusting screw, throttle dragline and condition of throttle 
work normally. 

No 

Repair and maintain as 
necessary 

Yes Next 

step 

3 

Check idling speed governor works normally. 

No 

Repair and maintain as 
necessary 

Yes 

Repair as necessary 

4 

A. Check the system is exhausted;    B. Check oil injector is blocked; 
C. Check pressure of oil supply system is too high. 

No Diagnosis 

help 

No.102 Malfunction code: P0508 "voltage of control circuit of idling 

speed governor too low"   

Serial No.  Operation steps 

Results   

Follow-ups   

 
 

 

 

150 

1 

Switch on diagnosis instrument and commutator, and place ignition switch 
to “ON”. 

 Next 

step 

Yes Next 

step 

2 

Take out connector of idling speed governor, and check resistance between 
A and D, B and C pins is around 53±5.3Ω under 20  with the multimeter.

℃

 

No 

Replace stepper 
motor 

Yes 

Repair or replace 
harness 

3 

Check lines among A, B, C D pins of idling speed governor and 65#, 66#, 
67#, 64# pins of ECU are shorted to ground. 

No Diagnosis 

help 

No.103 Malfunction code: P0509 "voltage of control circuit of idling 

speed governor too high"   

Serial No.  Operation steps 

Results   

Follow-ups   

1 

Switch on diagnosis instrument and commutator, and place ignition switch 
to “ON”. 

 Next 

step 

Yes Next 

step 

2 

Take out connector of idling speed governor, and check resistance between 
A and D, B and C pins is around 53±5.3Ω under 20  with the multimeter.

℃

 

No 

Replace stepper 
motor 

Yes 

Repair or replace 
harness 

3 

Check lines among A, B, C D pins of idling speed governor and 65#, 66#, 
67#, 64# pins of ECU are shorted to power source. 

No Diagnosis 

help 

No.104 Malfunction code: P0511 "malfunction control circuit of idling 

speed governor"   

Serial No.  Operation steps 

Results   

Follow-ups   

1 

Switch on diagnosis instrument and commutator, and place ignition switch 
to “ON”. 

 Next 

step 

Yes Next 

step 

2 

Take out connector of idling speed governor, and check resistance between 
A and D, B and C pins is around 53±5.3Ω under 20  with the multimeter.

℃

 

No 

Replace stepper 
motor  

Yes 

Repair or replace 
harness 

3 

Check lines among A, B, C D pins of idling speed governor and 65#, 66#, 
67#, 64# pins of ECU are opened. 

No Diagnosis 

help 

No.105 Malfunction code: P0560 "unreasonable system voltage signal"   

Serial No.  Operation steps 

Results   

Follow-ups   

1 

Switch on diagnosis instrument and commutator, and place ignition switch 
to “OFF”. 

 Next 

step 

Yes Next 

step 

2 

Check battery voltage is around 12V with the multimeter. 

No Replace 

battery 

cell

 
 

 

 

151 

Yes 

Repair or replace 
harness 

3 

Check lines among 44#, 45#, 63# pins of ECU and 87# pin of main relay 
are opened or shorted to ground. 

No Next 

step 

Yes Next 

step 

4 

Start the engine, and check charging voltage of generator is between 9-16V 
within different speed range. 

No Replace 

generator

Yes Diagnosis 

help 

5 

Check earth point of engine harness is good.   

No 

Repair or replace 
harness 

No.106 Malfunction code: P0562 "system voltage too low"   

Serial No.  Operation steps 

Results   

Follow-ups   

1 

Switch on diagnosis instrument and commutator, and place ignition switch 
to “OFF”. 

 Next 

step 

Yes Next 

step 

2 

Check battery voltage is around 12V with the multimeter. 

No Replace 

battery 

cell

Yes 

Repair or replace 
harness 

3 

Check resistance of lines between 44#, 45#, 63# pins of ECU and 87# pin 
of main relay are too large. 

No Next 

step 

Yes Next 

step 

4 

Start the engine, and check charging voltage of generator is between 9-16V 
within different speed range. 

No Replace 

generator

Yes Diagnosis 

help 

5 

Check earth point of engine harness is good. 

No 

Repair or replace 
harness 

No.107 Malfunction code: P0563 "system voltage too high"   

Serial No.  Operation steps 

Results   

Follow-ups   

1 

Switch on diagnosis instrument and commutator, and place ignition switch 
to “OFF”. 

 Next 

step 

Yes Next 

step 

2 

Check battery voltage is around 12V with the multimeter. 

No Replace 

battery 

cell

 
 

 

 

152 

Yes Next 

step 

3 

Start the engine, and check charging voltage of generator is between 9-16V 
within different speed range. 

No Replace 

generator

Yes Diagnosis 

help 

4 

Check earth point of engine harness is good. 

No 

Repair or replace 
harness 

No.108 Malfunction code: P0601 "error of check code of electronic 

control unit"   

Serial No.  Operation steps 

Results   

Follow-ups   

1 

Switch on diagnosis instrument, and place ignition switch at “ON”. 

 

Next step 

Yes Next 

step 

2 

Eliminate malfunction code, and reconfirm this malfunction is stable status 
malfunction. 

No System 

normal 

3 Replace 

ECU. 

End 

No.109 Malfunction code: P0602 "error of identification code of 

diagnosis data of electronic control unit"   

Serial No.  Operation steps 

Results   

Follow-ups   

1 

Switch on diagnosis instrument and commutator, and place ignition switch 
to “ON”. 

 Next 

step 

Yes Next 

step 

2 

Eliminate malfunction code, and reconfirm this malfunction is stable status 
malfunction. 

No System 

normal 

3 Replace 

ECU. 

End 

No.110 Malfunction code: P0645 "malfunction of relay control circuit of 

AC compressor"   

Serial No.  Operation steps 

Results   

Follow-ups   

1 

Switch on diagnosis instrument and commutator, and place ignition switch 
to “OFF”. 

 Next 

step