Cruise Control Malfunction
Cruise Control MalfunctionDiagnostic Instructions
^ Perform the [Diagnostic System Check - Vehicle Diagnostic Information] prior to using this diagnostic procedure. Diagnostic System Check - Vehicle Diagnostic Information
^ Review [Strategy Based Diagnosis] for an overview of the diagnostic approach. Strategy Based Diagnosis
^ [Diagnostic Procedure Instructions - Vehicle Diagnostic Information] provides an overview of each diagnostic category. Diagnostic Procedure Instructions - Vehicle Diagnostic Information
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 set/coast and resume/accelerate 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.
Conditions for Enabling Cruise Control
^ The vehicle speed is greater than 40 km/h (25 mph).
^ The vehicle is not in PARK, REVERSE, NEUTRAL, or 1st gear.
^ The system voltage is within 9-16 volts.
^ The park brake or brakes are not applied.
Circuit/System Verification
NOTE:
^ Repair any brake system related symptoms and DTCs before performing this diagnostic.
^ 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, Set, and Cancel as the applicable switch is pressed.
Circuit/System Testing
1. Ignition OFF, remove the inflatable restraint steering wheel module.
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 1 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 3 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 3 for a short to ground 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
NOTE: 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.
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.
Repair Instructions
Perform the [Diagnostic Repair Verification - Vehicle Diagnostic Information] after completing the diagnostic procedure. Diagnostic Repair Verification - Vehicle Diagnostic Information
^ [Steering Wheel Control Switch Assembly Replacement]