DTC P0505: Idle Speed Control (ISC) System <Vehicles for Hong kong>


DTC P0505: Idle Speed Control (ISC) System <Vehicles for Hong kong>

FUNCTION The amount of air taken in during idling is regulated by the opening and closing of the throttle valve. The engine-A/T-ECU checks the difference between the actual engine speed and the target engine speed.
TROUBLE JUDGMENT Check Conditions The vehicle speed has reached 1.5 km/h or more at least once. During the closed-loop idle speed control. Judgment Criterion The actual idle speed is higher than the target idle speed by 300 r/min or more for 10 seconds. Check Conditions The vehicle speed has reached 1.5 km/h or more at least once. During the closed-loop idle speed control. The highest ambient temperature at the last drive is 45°C or less. The engine coolant temperature is approximately 77°C or higher. The battery voltage is 10 V or more. The intake air temperature is -10°C or higher. Judgment Criterion The actual idle speed is higher than the target idle speed by 200 r/min or more for 10 seconds. Check Conditions During the closed-loop idle speed control The engine coolant temperature is approximately 77°C or higher. The battery voltage is 10 V or more. The power steering switch is in OFF position. The charging efficiency is 40% or less. The intake air temperature is -10°C or higher. Judgment Criteria The actual idle speed is lower than the target idle speed by 100 r/min or more for 10 seconds.
PROBABLE CAUSE Throttle valve area is dirty. Intake system vacuum leak. Failed engine-A/T-ECU



	STEP 1: MUT-II/III diagnosis code Q: Diagnosis code set? YES: Inspection chart for diagnosis code (Refer to .) NO: Go to Step 2 .
	STEP 2: Check throttle body (throttle valve portion) for contamination. Q: Is the check result normal? YES: Go to Step 3 . NO: Clean throttle body (throttle valve portion) (Refer to ).
	STEP 3. Check air intake from intake hose and inlet manifold. Q: Is the check result normal? YES: Go to Step 4 . NO: Repair.
	STEP 4. Check the trouble symptoms. Q: Does trouble symptom persist? YES: Replace engine-A/T-ECU. NO: Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points ).