Cruise Control Malfunction
Cruise Control Malfunction
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) 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)/powertrain control module (PCM). The ECM/PCM monitors the cruise control switch signal circuit in order to detect when a cruise control function switch has been requested. The ECM/PCM detects a predetermined voltage signal when a cruise control function switch is applied, with each switch having a different voltage value.
Diagnostic Aids
This diagnostic assumes the cruise control system is operating properly and no DTCs are set. If the cruise control system is malfunctioning, refer to Cruise Control Malfunction.
If any DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle (Diagnostic Trouble Code Descriptions).
Reference Information
Schematic Reference
Cruise Control Schematics (Electrical Diagrams)
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
Ignition ON, Cruise Control Switch ON, verify that the Cruise Set/Coast Switch and Resume/Accel switch parameters read Inactive (OFF). The switch parameter should change to Active (ON) and back to Inactive (OFF) as the appropriate switch is pressed and released. Road test the vehicle to ensure the cruise control system functions as described in Cruise Control Description and Operation (Description and Operation).
Circuit/System Testing
Important:
* Verify there are no DTCs set as current. If any DTCs are set as current, refer to Diagnostic Trouble Code (DTC) List - Vehicle (Diagnostic Trouble Code Descriptions) and perform the appropriate diagnostics/repairs before proceeding with symptom based diagnostics.
* Inspect the cruise control switches for any sticking or binding conditions.
* Inspect for proper operation of the stop lamps. Refer to Exterior Lighting Systems Description and Operation (Exterior Lighting Systems Description and Operation).
* With the ignition ON, cruise control On/Off switch ON, rotate the steering wheel to both steering stops while activating each cruise control switch separately. With a scan tool, observe all cruise control switch parameters in the ECM/PCM. Ensure that each cruise control switch activates and that each of the displayed switch position parameters match the currently activated switch, and do not read Invalid. This will aid in locating an intermittent fault within the inflatable restraint steering wheel module coil.
1. Ignition OFF, remove the inflatable restraint steering wheel module. Refer to Inflatable Restraint Steering Wheel Module Replacement (Service and Repair).
2. Disconnect the cruise control switch.
3. Ignition ON, measure for 10 volts or greater at the cruise control supply voltage circuit terminal 1.
• If less than the specified value, test the cruise control switch supply voltage circuit for an open/high resistance or a short to ground.
4. Ignition ON, verify that a test lamp illuminates between the cruise control supply voltage circuit terminal 1 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 or high resistance.
5. Ignition OFF, disconnect the harness connector X1 at the ECM/PCM.
6. Ignition ON, verify that a test lamp does not illuminate between the cruise control supply voltage circuit terminal 1 and the cruise control switch signal circuit terminal 3 of the cruise control switch harness.
• If the test lamp illuminates, test the cruise control switch signal circuit for a short to ground.
7. If the circuits test normal, test the cruise control switch. If the circuits and the component tests are normal, replace the ECM/PCM.
Component Testing
Important: The cruise control switch must be ON in order to properly measure the resistance of the set/cruise and the resume/accel switches.
1. Ignition OFF, remove the inflatable restraint steering wheel module. Refer to Inflatable Restraint Steering Wheel Module Replacement (Service and Repair).
2. Disconnect the cruise control switch.
3. Cruise control switch ON, measure the resistance between terminals 1 and 3 of the cruise control switch. Individually activate and hold each cruise control function switch and compare the resistance reading to the values in the table for the appropriate switch.
4. For the cancel switch, measure the resistance between terminals 1 and 5 of the cruise control switch. The meter reading should indicate O.L. with the switch released, and less than 1 ohm with the switch pressed.
• If any resistance measurements for any of the switches are not within the listed resistance values, replace the cruise control switch assembly.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* Steering Wheel Control Switch Assembly Replacement (Service and Repair)
* Control Module References (Programming and Relearning) for ECM or PCM replacement, setup, and programming