Operation CHARM: Car repair manuals for everyone.

Communication Circuit Troubleshooting

Cruise Control Communication Circuit Troubleshooting

A/T
1. Start the engine.
2. Turn on the cruise control main switch, then drive the vehicle at speeds over 25 mph (40 km/h) with the cruise control set.

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. 2005-2006 models: Connect the HDS to the data link connector (DLC). Select SCS mode using the HDS.
5. Disconnect PCM connector D (17P) and cruise control unit 14P connector.




6. 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 7.

7. Reconnect PCM connector D (17P) and the cruise control unit 14P connector.




8. Connect a voltmeter between cruise control unit 14P connector terminal No. 8 and 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 9.

NO - Replace the cruise control unit.




9. 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.