Cruise Control Malfunction
Cruise Control Malfunction
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Initial Inspection and Diagnostic Overview
* Review Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions provides an overview of each diagnostic category.
Circuit/System Description
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 switch signal circuit when a switch is applied. The BCM sends a serial data message to the engine control module (ECM), indicating the status of the cruise control switches.
Circuit/System Verification
Important: Electromagnetic interference (EMI) on the speed sensor signal circuit may cause erratic cruise control operation.
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 and Set as the applicable switch is pressed.
Circuit/System Testing
Important: Repair any brake system related symptoms and DTCs before performing this diagnostic.
1. Ignition OFF, remove the inflatable restraint steering wheel module. Refer to Inflatable Restraint Steering Wheel Module Replacement.
2. Disconnect the harness connector at the steering wheel controls switch - left.
3. Ignition ON, test for greater than 10 volts between the supply voltage circuit terminal 4 and ground.
• If less than the specified range, test the supply voltage circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.
4. Verify the scan tool Cruise Control Switch parameter is OFF.
• If not the specified value, test the signal circuit terminal 5 for a short to voltage. If the circuit tests normal, replace the BCM.
5. Ignition OFF, connect the harness connector at the steering wheel controls switch - left.
6. Ignition ON, with the cruise control switch in the ON position, observe the scan tool Cruise Control Switch parameter. The parameter should display ON.
• If not the specified value, test the signal circuit terminal 5 for a short to ground, a short to voltage or an open/high resistance. If the circuit tests normal, test or replace the steering wheel controls switch - left.
7. Observe the scan tool Cruise Control Switch parameter while pressing the RES + portion of the cruise control switch. The parameter should display Resume.
• If not the specified value, test or replace the steering wheel controls switch - left.
8. Observe the scan tool Cruise Control Switch parameter while pressing the SET - portion of the cruise control switch. The parameter should display Set.
• If not the specified value, test or replace the steering wheel controls switch - left.
9. Observe the scan tool Cruise Control Switch parameter while pressing the Cancel portion of the cruise control switch. The parameter should display Cancel.
• If not the specified value, test or replace the steering wheel controls switch - left.
10. If the circuits test normal, test or replace the ECM.
Component Testing
1. Ignition OFF, remove the inflatable restraint steering wheel module. Refer to Inflatable Restraint Steering Wheel Module Replacement.
2. Ignition OFF, disconnect the harness connector at the steering wheel controls - left.
3. Measure the resistance between terminals 4 and 5 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 for the On, Off, - SET and the + RES switches.
• If any of the resistance measurements for the On, Off, - SET, and the + RES switches are not within the listed resistance values, replace the steering wheel controls - left.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure. Verification Tests
* Steering Wheel Control Switch Assembly Replacement