Cruise Control Communication Circuit Troubleshooting

1.Start the engine.

2.Turn on the cruise control main 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 3.


NO - Check the cruise control unit or cruise control actuator.n


3.Turn the ignition switch OFF.

4.Disconnect the negative cable from the battery.

5.Disconnect Powertrain Control Module (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 short to ground in the wire between PCM connector terminal D12 and the cruise control unit 14P connector terminal No. 8.n


NO - Go to 7.


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

8.Connect the negative cable to the battery.

9.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 10.


NO - Substitute a known-good cruise control unit. If the system works properly, replace the  cruise control unit.n


10.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 necessary replace the PCM and recheck.n


NO - Repair open in the wire between PCM connector terminal D12 and the control unit 14P connector terminal No. 8.n