Test No. 12: Indicator Light Circuit
NOTE:
This procedure assumes instrument cluster power and ground circuits are okay.
- Turn ignition on. Check voltage at ECU connector terminal No. 7. With main cruise control switch on, 10-16 volts should exist. With main cruise control switch off, less than 1.2 volts should exist. If voltage is as specified, go to next test in DIAGNOSIS BY SYMPTOM table under TROUBLE SHOOTING. If voltage is not as specified, go to next step.
- Check GAUGE fuse. Replace as needed. Disconnect connector "D" from instrument cluster. See Fig 1. Turn ignition on. Check voltage at terminal D3. If battery voltage does not exist, repair open circuit between GAUGE fuse and instrument panel. If battery voltage exists, reconnect connector "D" to instrument panel and disconnect connector "A" from instrument panel.
- Connect jumper wire between ground and terminal No. 4 of disconnected instrument cluster connector (instrument cluster side of connector).
- Turn ignition on. If CRUISE indicator light does not come on, go to next step. If CRUISE indicator light comes on, check for faulty circuit between instrument cluster and cruise control ECU. Repair circuit if necessary. If circuit is okay, replace cruise control ECU.
- Check bulb and replace if necessary. If bulb is okay, replace instrument cluster circuit plate (printed circuit) with known good unit. If light works, replace circuit plate. If light does not work, replace instrument cluster computer and recheck system.