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 02: Traction Control Switch Circuit Short to Ground

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
TCS Switch Signal | B2745 02 | 1 | -- | --
Ground | -- | 1 | 1 | --
1. Traction Control Indicator Malfunction

### Circuit/System Description

The driver may disable the traction control system (TCS) by pressing the traction control switch. The body control module (BCM) detects the signal circuit is grounded and sends a serial data message to the electronic brake control module (EBCM) to disable traction control, and the instrument panel cluster (IPC) to illuminate the indicator.

### 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 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 DTC clears when the condition is no longer present.

### 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 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 Active and Inactive.

### 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 2 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 parameter is Inactive.

⇒ | If not the specified value, test the signal circuit terminal 1 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 1 and the ground circuit terminal 2. Verify the scan tool Traction Control Switch parameter is Active.

⇒ | 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 1 and the ground terminal 2 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 1 and the ground terminal 2 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 after completing the diagnostic procedure.

• | Electronic Traction Control Switch Replacement

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