3-Spoke Steering Wheel

DTC B3794 (3-Spoke Steering Wheel)

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.

DTC Descriptor

DTC B3794 08
- Cruise Control Function Request Circuit Signal Invalid

Diagnostic Fault Information






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. The BCM sends a serial data message to the engine control module (ECM), indicating the status of the cruise control switches.

Conditions for Running the DTC

* The ignition is ON.
* The cruise switch is ON.

Conditions for Setting the DTC

* The BCM detects an invalid voltage signal on the cruise control switch signal circuit.
* The above condition is present for 0.5 second.

Action Taken When the DTC Sets

* The BCM stores the DTC information into memory when the diagnostic runs and fails.
* The malfunction indicator lamp (MIL) will not illuminate.
* The cruise control system is disabled.

Conditions for Clearing the DTC

* The DTC becomes history when the conditions for setting the DTC are no longer present.
* The history DTC clears after 40 malfunction-free warm-up cycles.

Circuit/System Verification

Engine ON, observe the scan tool Cruise Control Switch parameter in the BCM while pressing the various cruise control switches. The reading should be toggle between On, Off, Resume and Set accordingly with the depressed switches.

Circuit/System Testing

1. Ignition OFF, remove the inflatable restraint steering wheel module. Refer to Inflatable Restraint Steering Wheel Module Replacement.
2. Disconnect the harness connector at the steering wheel controls switch - left.
3. Ignition ON, test for greater than 10 volts between the supply voltage circuit terminal 4 and ground.

• If less than the specified range, test the supply voltage circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.

4. Verify the scan tool Cruise Control Switch parameter is OFF.

• If not the specified value, test the signal circuit terminal 5 for a short to voltage. If the circuit tests normal, replace the BCM.

5. Ignition OFF, connect the harness connector at the steering wheel controls switch - left.
6. Ignition ON, with the cruise control switch in the ON position, observe the scan tool Cruise Control Switch parameter. The parameter should display ON.

• If not the specified value, test the signal circuit terminal 5 for a short to ground, a short to voltage or an open/high resistance. If the circuit tests normal, test or replace the steering wheel controls switch - left.

7. Observe the scan tool Cruise Control Switch parameter while pressing the RES + portion of the cruise control switch. The parameter should display Resume.

• If not the specified value, test or replace the steering wheel controls switch - left.

8. Observe the scan tool Cruise Control Switch parameter while pressing the SET- portion of the cruise control switch. The parameter should display Set.

• If not the specified value, test or replace the steering wheel controls switch - left.

9. Observe the scan tool Cruise Control Switch parameter while pressing the Cancel portion of the cruise control switch. The parameter should display Cancel.

• If not the specified value, test or replace the steering wheel controls switch - left.

10. If the circuits test normal, test or replace the BCM.

Component Testing

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

Steering Wheel Controls - Left
1. Ignition OFF, remove the inflatable restraint steering wheel module. Refer to Inflatable Restraint Steering Wheel Module Replacement.
2. Ignition OFF, disconnect the harness connector at the steering wheel controls - left.
3. Measure the resistance between terminals 4 and 5 (4 and 6 for the Cancel Switch) 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 for the ON/OFF, SET -, the RES +, and the Cancel switches.

• If any of the resistance measurements for the OFF, ON, - SET, + RES, and Cancel switches are not within the listed resistance values, replace the steering wheel controls - left switch assembly.






Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure. Verification Tests

* Steering Wheel Control Switch Assembly Replacement