Symptom Related Diagnostic Procedures

CRUISE CONTROL INOPERATIVE/MALFUNCTIONING

DIAGNOSTIC FAULT INFORMATION






IMPORTANT: Always perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Testing and Inspection

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 a cruise control function switch has been activated. The BCM detects a predetermined voltage signal when a cruise control function switch is applied, with each switch having a different voltage value.

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 is not applied.

DIAGNOSTIC AIDS
Perform the following to avoid misdiagnosis:
- Ensure that the following cruise control switches are not stuck in the engaged position:
- ON/OFF switch
- - Set switch
- + RES switch
- Inspect for proper operation of the stop lamps.
- Rotate the steering wheel to both steering stops while activating each cruise control switch separately. With a scan tool, observe the Cruise Control Switch parameter in the Body and Accessories, Cruise Control, BCM data list. Ensure that each cruise control switch activated and the displayed switch position in the Cruise Control Switch Parameter match as the steering wheel is turned. This will help eliminate the possibility of an internally open or shorted inflatable restraint steering wheel module coil.
- For an intermittent condition, refer to Testing for Intermittent Conditions and Poor Connections. Component Tests and General Diagnostics

CIRCUIT/SYSTEM TESTING

CAUTION:
- Refer to SIR Caution.
- Disable the inflatable restraint steering wheel module when performing this diagnostic. Refer to SIR Disabling and Enabling Zone 3.

1. With the ignition OFF, remove the inflatable restraint steering wheel module.
2. Disconnect the harness connector of the steering wheel controls switch.
3. With the ignition ON, measure for 10 volts or greater at the ignition 1 voltage circuit.
- If less than 10 volts, check for an open/high resistance or for a short to ground on the ignition 1 voltage circuit.
4. Test for a short to voltage in the cruise control set/coast and resume/accelerate switch signal circuit. Verify that a short is not present.
- Repair the short to voltage in the cruise control set/coast and resume/accelerate switch signal circuit.
5. Test for a short to ground, for an open, or for a high resistance in the cruise control set/coast and resume/accelerate switch signal circuit. Verify that a short or open is not present.
- Repair the short to ground, open, or high resistance in the cruise control set/coast and resume/accelerate switch signal circuit
6. Test the component. If the circuits and the component tests are normal, replace the BCM.

COMPONENT TESTING

CAUTION:
- Refer to SIR Caution.
- Disable the inflatable restraint steering wheel module when performing this diagnostic. Refer to SIR Disabling and Enabling Zone 3.

IMPORTANT: The cruise control ON/OFF switch must be ON in order to properly measure the resistance of the - SET and the + RES switches.




1. With the ignition OFF, remove the inflatable restraint steering wheel module.
2. With the ignition OFF, disconnect C3 at the inflatable restraint steering wheel module coil.
3. Measure the resistance between terminals C and D 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, and the + RES switches.
- If any of the resistance measurements for the OFF, ON, - SET, and the + RES switches are not within the listed resistance values, replace the cruise control switch.

REPAIR INSTRUCTIONS

IMPORTANT: Always perform the Diagnostic Repair Verification after completing the diagnostic procedure. Verification Tests

- Steering Wheel Control Switch Assembly Replacement
- Control Module References for BCM replacement, setup, and programming