Maintenance Manual for J2 Sedan
Electronic Control System
of Engine
224
S/N
Step
Check result
Subsequent step
always between 9V and 16V within different rotation speed ranges.
No
Replace the
generator
Yes
Diagnosis help
4
Check if the grounding point of engine harness is good.
No
Repair or replace
the harness
Fault code: P0602 “the programming of electronic control unit is in trouble”
S/N
Step
Check result
Subsequent step
1
Connect the diagnosis device and adapter, and turn the ignition switch
to ON position.
Next step
Yes
Next step
2
Eliminate the fault code and reconfirm if this fault is a steady fault.
No
The system is
normal.
3
Replace ECU.
End
Fault code: P0645 “the control circuit of A/C compressor relay is open”
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
To Step 4
2
Unplug the A/C compressor relay, turn the ignition key to “ON”
position, and check if the voltage between the relay power supply
side (namely Pins 87# and 85# of relay) and the negative pole of
power source is about 12V.
No
Next step
Yes
Repair or replace
the harness
3
Check if the circuit of relay power supply side is open or short to
ground.
No
To Step 2
Yes
Replace the relay
4
Check if the voltage between the control side of A/C compressor
relay (namely Pin 86# of relay) and the negative pole of power source
is about 3.7V.
No
Next step
Yes
Repair or replace
the harness
5
Check if the circuit connecting control side of A/C compressor relay
(namely Pin 86# of relay) to Pin 61# of ECU is open.
No
Diagnosis help
Fault code: P0646 “the control circuit of A/C compressor relay is short to ground”
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
To Step 4
2
Unplug the A/C compressor relay, turn the ignition key to “ON”
position, and check if the voltage between the relay power supply
side (namely Pins 87# and 85# of relay) and the negative pole of
power source is about 12V.
No
Next step
3
Check if the circuit of relay power supply side is open or short to
ground.
Yes
Repair or replace
the harness
