FI SYSTEM DIAGNOSIS 4-89
DTC “C65” (P0506/P0507): IDLE SPEED MALFUNCTION
DETECTED CONDITION AND POSSIBLE CAUSE
TROUBLESHOOTING
NOTE:
After repairing the trouble, clear the DTC using SDS tool. (
4-25)
Step 1
Engine combustion check
1) Run the engine at idle speed.
2) By spraying water to exhaust pipes from #1 and #2, check
evaporation from each of them to make sure for equal com-
bustion among cylinders.
Is check result OK?
Step 2
ISC valve initial check
1) Turn the ignition switch OFF.
2) Remove the ISC valve. (
5-18)
3) Connect the ISC valve coupler
1
.
4) Turn the ignition switch ON and then OFF again.
5) While performing above step 4), check that the ISC valve
moves from fully open position to fully closed position.
Is check result OK?
DETECTED CONDITION
POSSIBLE CAUSE
C65
Idle speed rose higher than or dropped
lower than desired idle speed by more
than specified range.
• Air passage clogged.
• ISC valve is fixed.
• Idle speed malfunction.
• Air leakage.
P0506
Idle speed dropped lower than desired
idle speed by more than specified
range.
P0507
Idle speed rose higher than desired idle
speed by more than specified range.
Be careful not to disconnect the ISC valve coupler at least 5 seconds after ignition switch is
turned to OFF.
If the ECM coupler is disconnected within 5 seconds after ignition switch is turned to OFF,
there is a possibility of an unusual value being written in the ECM and causing an error of ISC
valve operation.
YES
Go to Step 2.
NO
Repair or replace defective parts.
1
YES
Install the ISC valve (
5-20) and go to Step 3.
NO
Replace the ISC valve with a new one. (
5-20)
2
