Cruise Control Communication Circuit Troubleshooting

1. Start the engine.

1. Turn on the cruise control master switch, then drive the vehicle at 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.■

1. Turn the ignition switch OFF.

1. Connect the Honda Diagnostic System (HDS) to the data link connector (DLC). Turn the ignition switch ON (II), and jump the SCS line with the HDS, then turn the ignition switch OFF.
   NOTE: This step must be done to protect the powertrain control module (PCM) from damage.

1. Disconnect PCM connector D (17P) and cruise control unit 14P connector.

1. 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 .

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

1. 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 | - | Substitute a known-good cruise control unit. If the system works properly, replace the cruise control unit .■

1. 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 wire between the cruise control unit and 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.■