Diagnostic Instructions
| • | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
| • | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
| • | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
Diagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
Cruise Control Set/Coast and Resume/Accelerate Switch Signal Circuit | 1 | 1 | B3794 08 | -- |
Ignition 1 Voltage | 1 | 1 | P2535 | -- |
1. Cruise Control Inoperative/Malfunctioning | ||||
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. Refer to Exterior Lighting Systems Description and Operation . |
| • | 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. |
Reference Information
Schematic Reference
Connector End View Reference
Engine Control Module Connector End Views
Connector End View Reference
Electrical Information Reference
Circuit/System Testing
Caution: Refer to SIR Caution in the Preface section.
Disable the inflatable restraint steering wheel module when performing this diagnostic. Refer to SIR Disabling and Enabling .
- Ignition OFF, remove the inflatable restraint steering wheel module. Refer to Inflatable Restraint Steering Wheel Module Replacement .
- Disconnect the harness connector of the steering wheel controls switch.
- Ignition ON, measure for 10 volts or greater at the ignition 1 voltage circuit.
- 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.
- Test for an open, for a high resistance, or for a short to ground in the cruise control set/coast and resume/accelerate switch signal circuit. Verify that a short or open is not present.
- Test the component. If the circuits and the component tests are normal, test or replace the BCM.
| ⇒ | If less than 10 volts, check for an open, for a high resistance, or for a short to ground on the ignition 1 voltage circuit. |
| ⇒ | If present, repair the short to voltage in the cruise control set/coast and resume/accelerate switch signal circuit. |
| ⇒ | If present, repair the short to ground, open, or high resistance in the cruise control set/coast and resume/accelerate switch signal circuit |
Component Testing
Caution: Refer to SIR Caution in the Preface section.
Disable the inflatable restraint steering wheel module when performing this diagnostic. Refer to SIR Disabling and Enabling .
Important: The cruise control ON/OFF switch must be ON in order to properly measure the resistance of the - SET and the + RES switches.
- Ignition OFF, remove the inflatable restraint steering wheel module. Refer to Inflatable Restraint Steering Wheel Module Replacement .
- Ignition OFF, disconnect C3 at the inflatable restraint steering wheel module coil.
- 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. |
Function Switch | Minimum Resistance Value | Maximum Resistance Value |
|---|---|---|
OFF | O.L. | O.L. |
ON | 7.8k Ohms | 8.6k Ohms |
- SET | 2.7k Ohms | 3.0k Ohms |
+ RES | 1.2k Ohms | 1.3k Ohms |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for BCM replacement, setup, and programming |
