Test 8 (Ecu Power Source Circuit)

Cruise control ECU power source circuit supplies power to actuator and sensors. Cruise control ECU is grounded internally (through the case) and externally (through a ground wire).

1. Check ECU-IG fuse, located under left side of instrument panel, in junction block No. 1. If fuse is blown, repair short circuit. If fuse is okay, remove cruise control ECU, but leave electrical connector(s) attached.
2. Turn ignition on. Measure voltage between terminals no. 14 (+) and 13 (-) of cruise control ECU connector. See Figure.
3. If battery voltage is present, perform next procedure listed in DIAGNOSIS BY SYMPTOM  table. If battery voltage is not present, measure resistance between ground and terminal no. 13 of cruise control ECU connector. See Figure.
4. If resistance is one ohm or more, repair circuit between cruise control ECU and ground. If resistance is less than one ohm, repair circuit between battery and cruise control ECU.