P0505
DTC PO5O5IDLE CONTROL SYSTEM MALFUNCTION (ISC)
Description
- Idle air control solenoid valve consists of an air cut valve, duty control valve, intake air passage and a coolant passage.
- Air cut valve contains a bimetallic substance which responds to coolant temperature, and a duty control valve which is operated by a signal sent from Engine Control Module (ECM).
- When engine coolant temperature is low, air cut valve is fully opened by the action of the bimetallic substance so that the air flow required for low engine coolant temperatures is maintained.
- ECM controls duty control valve to bring the operating engine speed as close to preset idle speed as possible.
DTC Detecting Condition
Immediately at fault recognition.
Trouble Symptom
- Erroneous idling.
- Engine stalls.
- Engine breathing.
1. Check air intake system.
a. Turn ignition switch to "ON".
b. Start engine and idle it.
c. Check intake manifold idle air control solenoid valve and throttle body for loose installation and gasket for cracks.
d. Check by-pass hoses for loose connections and cracks.
e. Check vacuum hoses for disconnections.
2. Check output signal from ECM.
a. Turn ignition switch to "ON".
b. Measure voltage between ECM and body.
[CHECK]: Connector & terminal:
(B84) No. 11 - Body/3 Volts or more.
(B84) No. 12 - Body/3 Volts or more.
[NO]: Go to step 4.
[YES]: Go to the next step.
c. Turn ignition switch to "OFF".
d. Disconnect connector from idle air control solenoid valve.
e. Turn ignition switch to "ON".
f. Measure voltage between ECM and body.
[CHECK]: Connector & terminal:
(B84) No. 11 - Body/10 Volts or more.
(B84) No. 12 - Body/10 Volts or more.
[YES]: Repair short circuit of harness and replace ECM.
[NO]: Go to next [CHECK].
[CHECK]: Is there poor contact in ECM connector?
[YES]: Repair poor contact in ECM connector.
[NO]: Go to step 3.
3. Check idle air control solenoid valve.
a. Turn ignition switch to "OFF".
b. Measure resistance between solenoid valve terminals.
[CHECK]: Terminals:
No. 1 - No. 2/20 Ohms or more.
No. 2 - No. 3/20 Ohms or more.
[YES]: Replace idle air control solenoid valve.
[NO]: Go to next [CHECK].
[CHECK]: Terminals:
No. 1 - No. 2/5 Ohms or less.
No. 2 - No. 3/5 Ohms or less.
[YES]: Replace idle air control solenoid valve and ECM.
[NO]: Go to next step.
c. Remove idle air control solenoid valve.
d. Check operation of idle air control solenoid valve.
[CHECK]: When connecting the Battery to terminals No. 1 and No. 2 of idle air control solenoid valve, check if it is fully opened.
[YES]: Go to next [CHECK].
[NO]: Clean idle air control solenoid valve.
[CHECK]: When connecting the battery to terminals No. 3 and No. 2 of idle air control solenoid valve, check if it is fully closed.
[YES]: Go to step 4.
[NO]: Clean idle air control solenoid valve.
4. Check power supply to idle air control solenoid valve.
a. Turn ignition switch to "OFF".
b. Disconnect connector from idle air control solenoid valve.
c. Turn ignition switch to "ON".
d. Measure voltage between idle air control solenoid valve and body.
[CHECK]: Connector & terminal:
(E7) No. 2 - Body/10 Volts or more.
[YES]: Go to step 5.
[NO]: Repair open circuit of harness between idle air control solenoid valve connector and ECM connector.
5. Check harness connector between ECM and idle air control solenoid valve.
a. Turn ignition switch to "OFF".
b. Disconnect connector from ECM.
c. Measure resistance of harness connector between ECM and idle air control solenoid valve.
[CHECK]: Connector & terminal:
(B84) No. 11 - (E7) No. 1/10 Ohms or less.
(B84) No. 12 - (E7) No. 3/10 Ohms or less.
[NO]: Repair open circuit of harness between ECM connector and idle air control solenoid valve connector.
[YES]: Go to the next step.
d. Measure resistance of harness connector between ECM and body to make sure that circuit does not short.
[CHECK]: Connector & terminal:
(B84) No. 11 - Body/1 M-Ohms or more.
(B84) No. 12 - Body/1 M-Ohms or more.
[YES]: Confirm good condition in connectors of idle air control solenoid valve circuit.
[NO]: Repair short circuit of harness between ECM connector and idle air control solenoid valve connector.