For 1990-2009 cars

### Circuit 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.

### DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC B2745 Traction Control Switch Circuit

### Conditions for Running the DTC

The ignition is 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 DTC clears automatically from Current status when the fault is corrected. Use a scan tool to clear the DTC from History status.

### Diagnostic Aids

An intermittent short to ground on the traction control signal circuit is the most likely cause of a history DTC when no problem is found. When the Conditions for Setting this DTC are present, the driver is not able to disable traction control.

### Test Description

The number below refers to the step number on the diagnostic table.

1. This step tests for a short to ground within the traction control switch. DTC B0828 may set during this step.

Step | Action | Value | Yes | No
--- | --- | --- | --- | ---
Schematic Reference: Antilock Brake System Schematics and Body Control System Schematics Connector End View Reference: Antilock Brake System Connector End Views and Data Communication Connector End Views
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | Go to Diagnostic System Check - Vehicle
2 |

1. Turn OFF the ignition for 5 seconds.
2. Turn ON the ignition and wait at least 60 seconds for the DTC to reset.

Does DTC B2745 set as a Current DTC?

--

Go to Step 3

Go to Diagnostic Aids

3 |

1. Turn OFF the ignition.
2. Remove the instrument panel center trim bezel to access the traction control switch harness connector.
3. Disconnect the traction control switch harness connector.
4. Turn ON the ignition.

Does the DTC set?

--

Go to Step 4

Go to Step 7

4 | Use a DMM to measure the voltage between the traction control signal circuit and a good ground. Does the voltage measure greater than the specified value? | 11 V | Go to Step 6 | Go to Step 5
5 | Test the traction control signal circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 8 | Go to Step 6
6 | Replace the body control module (BCM). Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement? | -- | Go to Step 8 | --
7 | Replace the traction control switch. Refer to Accessory Switch Replacement . Did you complete the replacement? | -- | Go to Step 8 | --
8 |

1. Use the scan tool to clear the DTCs.
2. Operate the vehicle within the Conditions for Running the DTC, as specified in the supporting text.

Does the DTC reset?

--

Go to Step 3

System OK