Cruise Control Malfunction
Cruise Control Malfunction
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (Diagnostic System Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Strategy Based Diagnosis) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Diagnostic Procedure Instructions) provides an overview of each diagnostic category.
Diagnostic Fault Information
Circuit/System Description
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.
Reference Information
Schematic Reference
Cruise Control Schematics ([1][2]Cruise Control)
Connector End View Reference
Component Connector End Views (Connector Views)
Description and Operation
Cruise Control Description and Operation (Description and Operation)
Electrical Information Reference
* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)
Scan Tool Reference
Control Module References (Programming and Relearning) for scan tool information
Circuit/System Verification
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, disconnect the X201 harness connector at the turn signal/multifunction switch.
2. Ignition ON, test for B+ between the B+ circuit terminal A8 and ground.
• If less than the specified value, test the 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 B8 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 B8 and the B+ circuit terminal A8. Verify the scan tool Cruise ON/OFF Switch parameter displays ON.
• If not the specified value, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the ECM.
5. If all circuits test normal, test or replace the turn signal/multifunction switch.
Component Testing
1. Disconnect the X201 steering column harness connector.
2. Cruise control switch ON, measure the resistance between terminal A8 and terminal B8 while individually activating and holding each cruise control function switch and compare the resistance reading to the values in the table below.
• If not within the specified resistance range, replace the turn signal/multifunction switch.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* Turn Signal Multifunction Switch Replacement (Turn Signal Multifunction Switch Replacement)
* Control Module References (Programming and Relearning) for ECM replacement, setup, and programming