The cruise control switch is an input to the engine control module (ECM). The ECM monitors the cruise control switch signal circuit in order to detect when a cruise control function has been requested. The ECM detects a specific voltage signal on the cruise control switch signal circuit when a cruise control function switch is activated, with each switch having a different predetermined voltage value. The BCM monitors the cruise control cancel switch signal circuit and also sends a serial data message to the ECM indicating the status of the cruise cancel switch.

Schematic Reference

Cruise Control Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Cruise Control Description and Operation

Electrical Information Reference

Scan Tool Reference

Control Module References for scan tool information

Engine ON, while rotating the steering wheel to both steering stops, observe the scan tool Cruise Control Switch parameter while pressing each of the cruise control switches. The parameter should toggle between ON, OFF, Resume, Set, as the applicable switch is pressed.

1. Ignition OFF, disconnect the harness connector at the cruise control switch.
2. Ignition ON, test for B+ between the ignition voltage circuit terminal 2 and ground.

⇒	If less than the specified value, test the ignition voltage circuit for a short to ground or an open/high resistance.

3. Verify the scan tool Cruise ON/OFF switch parameter displays OFF.

⇒	If not the specified value, test the signal circuit terminal 1 for a short to voltage. If the circuit tests normal, replace the ECM.

4. Install a 3A fused jumper wire between the signal circuit terminal 1 and the B+ ignition voltage circuit terminal 2. Verify the scan tool Cruise ON/OFF Switch parameter displays ON.

⇒	If not the specified value, test the signal circuit terminal 1 for a short to ground or an open/high resistance. If the circuit tests normal, replace the ECM.

5. Verify the scan tool Cruise Cancel switch parameter displays Inactive.

⇒	If not the specified value, test the signal circuit terminal 3 for a short to voltage. If the circuit tests normal, replace the BCM.

6. Install a 3A fused jumper wire between the signal circuit terminal 3 and the B+ ignition voltage circuit terminal 2. Verify the scan tool Cruise Cancel Switch parameter displays Active.

⇒	If not the specified value, test the signal circuit terminal 3 for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.

7. If all circuits test normal, test or replace the turn cruise control switch.

Important: The cruise control switch must be ON in order to properly measure the resistance of the - /SET, +/RES, switches.

1. Ignition OFF, disconnect the harness connector at the cruise control switch.
2. Cruise control switch ON, measure the resistance between terminals 2 and 1 or for the Cancel switch 2 and 3 on the cruise control switch side of the connector. Individually activate and hold each cruise control function switch and compare the resistance reading to the values in the table for the appropriate switch.

⇒	If any of the resistance measurements for the individual switches are not within the specified resistance values, replace the cruise control switch.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.