Idle Switch Circuit
NOTE:
Ensure Throttle Position (TP) sensor adjustment and operation are normal. See ON-VEHICLE ADJUSTMENTS article in ENGINE PERFORMANCE section. Adjust or replace TP sensor as necessary.
- Remove the cruise control ECU with the connector connected. Disconnect Engine Control Module (ECM) and Anti-Lock Brake System (ABS) ECU connectors. ECM is located behind right kick panel. See Figure. ABS ECU is located behind center of instrument panel. Turn ignition switch to ON position. Backprobing cruise control ECU, measure voltage between ground and cruise control ECU connector terminal No. 8 (Yellow/Blue wire).
- With throttle valve fully open, battery voltage should exist. With throttle valve fully closed, voltage should be less than 2 volts. If voltage is not as specified, go to next step. If voltage is as specified, no problem is indicated at this time. Fault may be intermittent. If sent here from SYMPTOM DIAGNOSIS, perform next test listed.
- Disconnect TP sensor 3-pin connector. Measure resistance between TP sensor terminals No. 1 and No. 3. See Fig 1. Resistance should be 2000-10,200 ohms with throttle valve fully opened, and 200-5700 ohms with throttle valve fully closed. If resistance is as specified, go to next step. If resistance is not as specified, replace TP sensor and retest system.
- Check wiring harness and connectors between cruise control ECU and TP sensor, and between TP sensor and ground. Repair as necessary and retest system. If wiring harness and connectors are okay, replace cruise control ECU and retest system.