B3794

DTC B3794

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Diagnostic System Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Strategy Based Diagnosis) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Diagnostic Procedure Instructions) provides an overview of each diagnostic category.

DTC Descriptor
DTC B3794
- Cruise Control Function Request Circuit Signal Invalid

Diagnostic Fault Information





Circuit/System Description

The cruise control switch is an input to the instrument panel cluster (IPC). The IPC 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 IPC detects a specific voltage signal on the cruise control switch signal circuit when a switch is applied. The IPC 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 IPC detects an invalid voltage signal on the cruise control switch signal circuit.

Action Taken When the DTC Sets

The cruise control system is disabled.

Conditions for Clearing the DTC

The current DTC clears when the fault is no longer present.

Reference Information
Schematic Reference

Cruise Control Schematics (Electrical Diagrams)
Connector End View Reference

Component Connector End Views (Connector Views)
Description and Operation

Cruise Control Description and Operation (Description and Operation)
Electrical Information Reference

* Circuit Testing (Circuit Testing)
* Connector Repairs (Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (Wiring Repairs)

Circuit/System Verification

Ignition ON, observe the scan tool Cruise Mode Signal parameter. The reading should be 0.0 V and change when the cruise control switch is turned ON, and while the resume and set switches are pressed.

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the cruise control switch.
2. Ignition ON, test for 11-13 V between the ignition reference circuit terminal 4 and ground.

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

3. Verify the scan tool Cruise Mode Signal parameter is less than 1 V.

• If greater than the specified range, test the signal circuit terminal 1 for a short to voltage. If the circuit tests normal, replace the IPC.

4. Install a 3A fused jumper wire between the signal circuit terminal 1 and the ignition reference circuit terminal 4. Verify the scan tool Cruise Mode Signal parameter is greater than 11 V.

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

5. If all circuits test normal, test or replace the cruise control switch.

Repair Instructions

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

* Cruise Control Switch Replacement (Service and Repair)
* Control Module References (Programming and Relearning) for IPC replacement, programming, and setup.