B2745

DTC B2745

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 B2745
- Traction Control Switch Circuit

Diagnostic Fault Information





Circuit/System Description

The driver may disable the Traction Control System (TCS) by pressing the traction control switch. The body control module (BCM) supplies a 12 volt signal on the traction control signal circuit. When the traction control switch is pressed, this voltage signal is grounded.

Conditions for Running the DTC

Ignition ON.

Conditions for Setting the DTC

The BCM detects low voltage on the traction control signal circuit for 60 seconds.

Action Taken When the DTC Sets

* The BCM sends a serial data message to the electronic brake control module (EBCM) informing the EBCM that the desired TCS state cannot be determined.
* A DIC message and/or warning message may be displayed.

Conditions for Clearing the DTC

* The condition for the DTC is no longer present.
* The EBCM clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles.

Reference Information
Schematic Reference

Antilock Brake System Schematics (Electrical Diagrams)
Connector End View Reference

Component Connector End Views (Connector End Views By Name)
Description and Operation

ABS Description and Operation (Description and Operation)
Electrical Information Reference

* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)

Scan Tool Reference

Control Module References (Programming and Relearning) for scan tool information.

Circuit/System Verification

Ignition ON, observe the scan tool BCM Traction Control Switch parameter while pressing and releasing the Traction Control Switch. The reading should change between Pressed and Released.

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the traction control switch.
2. Test for less than 5 ohms between the ground circuit terminal 13 and ground.

• If greater than the specified range, test the ground circuit for an open/high resistance.

3. Ignition ON, verify the scan tool Traction Control Switch State parameter is Released.

• If not the specified value, test the signal circuit terminal 14 for a short to ground. If the circuit tests normal, replace the BCM.

4. Install a 3A fused jumper wire between the signal circuit terminal 14 and the ground circuit terminal 13. Verify the scan tool Traction Control Switch State parameter is Pressed.

• If not the specified value, test the signal circuit for an open/high resistance. If the circuit tests normal, replace the BCM.

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

Component Testing

1. Ignition OFF, disconnect the harness connector at the traction control switch.
2. Test for infinite resistance between the signal terminal 14 and the ground terminal 13 with the switch in the open position.

• If not the specified value, replace the traction control switch.

3. Test for less than 3 ohms between the signal terminal 14 and the ground terminal 13 with the switch in the closed position.

• If greater than the specified range, replace the traction control switch.

Repair Instructions

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

* Accessory Switch Replacement (Service and Repair)
* Control Module References (Programming and Relearning) for BCM replacement, setup, and programming