Communication Circuit Troubleshooting
Cruise Control Communication Circuit TroubleshootingA/T
1. Start the engine.
2. Turn on the cruise control master switch, then drive the vehicle to speeds over 25 mph (40 km/h) with the cruise control.
Does the cruise control operate?
YES - Go to step 3.
NO - Check the cruise control unit or cruise control actuator.
3. Turn the ignition switch OFF.
4. Disconnect PCM connector D (17P) and cruise control unit 14P connector.
5. Check for continuity between PCM connector terminal D12 and body ground.
Is there continuity?
YES - Repair a short to ground in the wire between PCM connector terminal D12 and the cruise control unit 14P connector terminal No. 8.
NO - Go to step 6.
6. Reconnect PCM connector D (17P) and the cruise control unit 14P connector.
7. Connect a voltmeter between cruise control unit 14P connector terminal No. Sand body ground. Test-drive the vehicle at speeds over 25 mph (40 km/h) with the cruise control set, and watch the voltmeter.
Is there about 1 V?
YES - Go to step 8.
NO - Replace the cruise control unit.
8. Connect a voltmeter between PCM connector terminal D12 and body ground. Drive the vehicle at speeds over 25 mph (40 km/h) with the cruise control set, and watch the voltmeter.
Is there about 1 V?
YES - Check for loose connectors of the BLU/ORN wire between the cruise control unit and the PCM. If the wire is OK, update the PCM if it does not have the latest software, or substitute a known-good PCM, and recheck. If the system works properly, replace the original PCM.
NO - Repair an open in the wire between PCM connector terminal D12 and the control unit 14P connector terminal No. 8.