Idle Control System

DTC Troubleshooting

11-556  

DTC 14: IAC Valve Circuit Malfunction

  1. Reset the ECM/PCM (see page 11-468).
  2. Turn the ignition switch ON (II).

Is the MIL on and does it indicate DTC 14?

YES

- Go to step 3.

NO

- Intermittent failure, system is OK at this time. Check for poor connections or loose wires at the IAC valve and at the ECM/PCM.


  1. Turn the ignition switch OFF.
  2. Disconnect the IAC valve 3P connector.
  3. Turn the ignition switch ON (II).
  4. Measure voltage between the IAC valve 3P connector terminal No. 2 and body ground.

IAC VALVE 3P CONNECTOR

Wire side of female terminals

Is there battery voltage?

YES

- Go to step 7.

NO

- Repair open in the wire between the IAC valve and the PGM-FI main relay.


  1. Turn the ignition switch OFF.

  1. Check for continuity between body ground and the IAC valve 3P connector terminal No. 1.

IAC VALVE 3P CONNECTOR

Wire side female terminals

Is there continuity?

YES

- Go to step 9.

NO

- Repair open in the wire between the IAC valve and G101.


  1. Disconnect ECM/PCM connector A (31P).
  2. Check for continuity between body ground and ECM/PCM connector terminal A12.

ECM/PCM CONNECTOR A (31P)

Wire side of female terminals

Is there continuity?

YES

- Repair short in the wire between the IAC valve and the ECM/PCM (A12).

NO

- Go to step 11.