Cruise Control Ecu Power Source Circuit
- Locate ECU-IG (10-amp) fuse in instrument panel junction block. See Figure. Remove ECU-IG fuse and ensure fuse continuity. If fuse is okay, go to next step. If fuse is not okay, check for short between cruise control ECU connector terminal No. 9 (Black/Yellow wire) and ECU-IG fuse.
- Remove cruise control ECU with connector attached. See Figure. Turn ignition switch to ON position. Measure voltage by backprobing between cruise control ECU connector terminals No. 9 (Black/Yellow wire) and No. 16 (White/Black wire). If battery voltage is not present, go to next step. If battery voltage is present, no problem is indicated at this time. Fault may be intermittent. If sent here from SYMPTOM TESTS, perform next test under appropriate symptom.
- Turn ignition switch to OFF position. Measure resistance by backprobing between cruise control ECU connector terminal No. 16 (White/Black wire) and ground. If resistance is less than one ohm, check wiring harness or connector between cruise control ECU connector and battery. Repair as necessary and retest system. If resistance is one ohm or more, repair wiring harness or connector between cruise control ECU connector terminal No. 16 and ground. Retest system.