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 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.
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.
Diagnostic Aids
Caution: Refer to Restraint System Service Precautions.
Important: Repair any brake system related symptoms and DTCs before performing this diagnostic.
Disable the inflatable restraint steering wheel module when performing this diagnostic table. Refer to SIR Disabling and Enabling.
In order to avoid misdiagnosis, inspect for the following:
* Verify there are no DTCs set as current. If any DTCs are set as current, refer to Diagnostic Trouble Code (DTC) List - Vehicle and perform the appropriate diagnostics/repairs before proceeding with symptom based diagnostics. Diagnostic Trouble Code Descriptions
* Inspect the cruise control switches for any sticking or binding conditions.
* Inspect for proper operation of the stop lamps.
* With the ignition 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. Ensure that each cruise control switch activated and that each displayed switch position parameters do not match or reads Error, this will aid in locating an intermittent fault within the inflatable restraint steering wheel module coil.
Circuit/System Verification
Ignition ON, cruise on/off switch ON. With a scan tool, observe the Cruise Control Switch parameter in the BCM. Verify that the Cruise Control Switch parameter changes to match accordingly for each switch as it is activated and released. Road test the vehicle to ensure the cruise control system functions as described in Cruise Control Description and Operation.
Circuit/System Testing
Caution: Refer to Restraint System Service Precautions.
Disable the inflatable restraint steering wheel module when performing this diagnostic. Refer to SIR Disabling and Enabling.
1. Ignition OFF, remove the inflatable restraint steering wheel module.
2. Disconnect the harness connector of the cruise control switch.
3. Ignition ON, measure for 10 volts or greater between the steering wheel switch harness terminal 1 and ground.
• If less than 10 volts, test for an open/high resistance or a short to ground on the cruise control supply voltage circuit.
4. Ignition OFF, disconnect the harness connector X1 at the BCM.
5. Test for 1.0 ohm or less resistance between the cruise control switch harness terminal 3 and the BCM X1 connector terminal 3.
• If greater than the specified range, test the cruise control switch signal circuit for an open/high resistance.
6. Test for infinite resistance between the cruise control switch harness terminal 3 and ground.
• If less than the specified range, test the cruise control switch signal circuit for a short to ground.
7. Ignition ON, test for 0 volts between the cruise control switch harness terminal 3 and ground.
• If greater than the specified value, test the cruise control switch signal circuit for a short to voltage.
8. If all circuits test normal, test the component. If the component tests normal, replace the BCM.
Component Testing
Caution: Refer to Restraint System Service Precautions.
Disable the inflatable restraint steering wheel module when performing this diagnostic. Refer to SIR Disabling and Enabling.
Important: The cruise control switch must be ON in order to properly measure the resistance of the - SET, the + RES, and the Cancel switches.
1. With the ignition OFF, remove the inflatable restraint steering wheel module.
2. With the ignition OFF, disconnect X277 at the inflatable restraint steering wheel module coil.
3. Measure the resistance between terminals E and C 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 each of the cruise control switches.
• If any of the 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 after completing the diagnostic procedure. Verification Tests
* Steering Wheel Control Switch Assembly Replacement