The cruise control switch is an input to the body control module (BCM). The BCM monitors the cruise control set/coast and resume/accelerate switch signal circuit in order to detect when the driver has requested to perform a cruise control function. The BCM detects a specific voltage signal on the cruise control set/coast and resume/accelerate switch signal circuit when a switch is applied. The BCM sends a GMLAN serial data message to the ECM indicating the status of the cruise control switches.

Schematic Reference

Cruise Control Schematics

Connector End View Reference

Cruise Control Connector End Views

Electrical Information Reference

Important: Repair any brake system related symptoms and DTCs before performing this diagnostic.

Important: If a BCM has been replaced, the brake pedal position (BPP) sensor must be calibrated. Refer to Brake Pedal Position Sensor Calibration .

Ignition ON, observe the scan tool Cruise Control Switch parameter while pressing the cruise control switches. The reading should change between On, Off, Resume, Set and Cancel accordingly with the depressed switches.

1. Ignition OFF, remove the inflatable restraint steering wheel module. Refer to Inflatable Restraint Steering Wheel Module Replacement .
2. Disconnect the harness connector of the steering wheel controls switch - left.
3. Ignition ON, test for 10 volts or greater between the steering wheel control supply voltage circuit terminal 1 and ground.

⇒	If less than 10 volts, check for an open/high resistance or for a short to ground on the steering wheel control supply voltage circuit. If the circuit tests normal, replace the BCM.

4. Ignition ON, verify that a test lamp illuminates between B+ and the cruise control switch signal circuit terminal 3.

⇒	If the test lamp does not illuminate, test the cruise control switch signal circuit for an open/high resistance. If the circuit tests normal, replace the BCM.

5. Ignition OFF, disconnect the harness connector C1 at the BCM.
6. Measure for 0 volts between the cruise control switch signal circuit terminal 3 and ground.

⇒	If greater than the specified value, test the cruise control switch signal circuit for a short to voltage.

7. If all circuits test normal, test the component. If the circuits and the component tests are normal, replace the BCM.

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

Steering Wheel Controls Switch - Left

1. Ignition OFF, remove the inflatable restraint steering wheel module. Refer to Inflatable Restraint Steering Wheel Module Replacement .
2. Ignition OFF, disconnect the steering wheel controls switch - left.
3. Cruise switch ON, measure the resistance between terminals 1 and 3 at 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 on the schematic for the ON/OFF, SET -, the RES +, and the Cancel switches.

⇒	If any of the resistance measurements for the OFF, ON, SET -, RES + and Cancel switches are not within the listed resistance values, replace the steering wheel controls switch - left.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.