Idle and (IAC) System

Fig. 23 Idle Up compensator signal test connections:

The idle up system should operate when the running lights, heater fan, cooling fan, or rear defogger are put into operation. If idle up actuator fails to operate when any of these accessories are switched on, check if proper signal is sent to ECM as follows:
1. Disconnect ECM connector.
2. Switch on ignition without starting engine.
3. Connect voltmeter between terminal 7 and body (ground), Fig. 23. Activate each component as mentioned previously. If voltmeter reads 11-14 volts as each component is activated, the idle up signal is being sent to the ECM. If reading of 11-14 volts is not obtained, circuit is making poor contact or is open. Correct as necessary.
4. Reconnect ECM connector securely.