For 1990-2009 cars

### 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.

### DTC Descriptor

DTC B2745 00: Traction Control Switch Circuit

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
TCS switch signal circuit | B2745 | 1 | -- | --
Ground | -- | 1 | -- | --
1. Traction control cannot be manually disabled.

### 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.

• | The EBCM defaults the TCS status to enabled.

### Conditions for Clearing the DTC

• | The condition for setting 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

#### Connector End View Reference

Component Connector End Views

#### Description and Operation

ABS Description and Operation

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

#### Scan Tool Reference

Control Module References for scan tool information.

### Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the traction control switch.
2. Ignition ON, verify the scan tool BCM TCS Switch State parameter is Released.

⇒ | If not the specified value, test the signal circuit terminal I for a short to ground.

3. Install a 3A fused jumper wire between the signal circuit terminal I and the ground circuit terminal H. Verify the scan tool BCM TCS Switch State parameter is Pressed.

⇒ | If not the specified value, test the signal circuit for a short to voltage or an open/high resistance.

4. If all circuits test normal, test or replace the traction control switch. If DTC resets replace the BCM.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Accessory Switch Replacement

• | Control Module References for BCM replacement, setup, and programming.