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B3794



DTC B3794

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 set/coast and resume/accelerate 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 cruise switch is ON.
* The ignition 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 greater than 1 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 fault is no longer present.
* A history DTC clears after 100 malfunction-free ignition cycles.
* The BCM receives a clear code command from the scan tool.

Circuit/System Verification

Engine ON, while rotating the steering wheel to both steering stops, observe the scan tool Cruise Control Switch parameter while pressing each of the cruise control switches. The parameter should toggle between On, Off, Resume and Set as the applicable switch is pressed.

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 5 (UK3)/3 (non UK3) 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. Ignition OFF, connect the harness connector at the steering wheel controls switch - left.
5. Ignition OFF, disconnect the harness connector at the steering wheel controls switch - right.
6. Ignition ON, cruise switch ON, test for greater than 10 volts between the supply voltage circuit terminal 6 (UK3)/3 (non UK3) 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, test or replace the steering wheel controls - left.

7. 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.

8. Ignition OFF, connect the harness connector at the steering wheel controls switch - right.
9. Ignition ON, cruise switch ON, observe the scan tool Cruise Control Switch parameter. The parameter should display ON.

• If not the specified value, test the signal circuit terminal 7 (UK3)/4 (non UK3) 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 - right.

10. 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 - right.

11. 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 - right.

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

Component Testing

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 control - left and the steering wheel controls - right.
3. Measure the resistance between terminals 5 (UK3)/3 (non UK3) and 6 at the steering wheel controls - left. Then measure the resistance between terminals 7 (UK3)/4 (non UK3) and 6 (UK3)/3 (non UK3) at the steering wheel controls - right. Individually activate and hold each cruise control function switch and compare the resistance reading to the values for the On, Off, - SET and the + RES switches.

• If any of the resistance measurements for the On or Off switches are not within the listed resistance values, replace the steering wheel controls - left.

• If any of the resistance measurements for the - SET, + RES, and neutral position switches are not within the listed resistance values, replace the steering wheel controls - right.






Repair Instructions

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

* Steering Wheel Control Switch Assembly Replacement
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