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 Short To Ground

### Circuit/System Description

The electronic stability program (ESP) switch is a normally open switch that closes when the switch is activated. When activated, the switch grounds the ESP signal circuit. The body control module (BCM) converts the signal into serial data, which is used by the electronic brake control module (EBCM) to enable/disable the ESP. ESP status is displayed on the instrument cluster.

### Conditions for Running the DTC

• | The ignition is ON.

• | Ignition voltage is between 9 and 16 volts.

### Conditions for Setting the DTC

The BCM detects the ESP switch is activated for 60 seconds or more.

### Action Taken When the DTC Sets

The multi function display (MFD) displays the ESP Off message.

### Conditions for Clearing the DTC

• | The conditions for setting the DTC are no longer present.

• | A history DTC clears after 40 fault-free ignition cycles.

• | The DTC can be cleared using a scan tool.

### Reference Information

#### Schematic Reference

Antilock Brake System Schematics .

#### Connector End View Reference

Component Connector End Views

#### Electrical Information Reference

• | Circuit Testing .

• | Connector Repairs .

• | Testing for Intermittent Conditions and Poor Connections .

• | Wiring Repairs .

#### Scan Tool Reference

Control Module References

### Circuit/System Verification

With the vehicle in park or neutral, handbrake applied, and engine running observe the scan tool while operating the ESP switch. The scan tool display should switch from ESP ON to OFF as the switch is switched between states.

### Circuit/System Testing

1. Verify that no other DTCs are set.
2. Ignition ON, using the scan tool observe the ESP parameter while activating/deactivating the ESP switch. The scan tool should verify a change of state in the ESP system.

⇒ | If the ESP does not change state, disconnect the ESP/TCS switch harness connector. Connect a test light between a known ground and the signal circuit of the wiring harness.

⇒ | If test light does not illuminate test the signal circuit for an open/high resistance or short to ground. If the circuit tests normal, replace the BCM.

3. Reconnect the wiring harness to the ESP/TCS.
4. Test for less than 1 ohm resistance between the ESP/TCS switch ground circuit and a known ground.

⇒ | If greater than specified range, test the ESP/TCS ground circuit for open/high resistance. If the circuit tests normal, replace the ESP/TCS switch.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Electronic Stability Program Switch Testing

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