GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The traction control switch is a momentary-contact, normally-open switch that can be used to disable the traction control system (TCS). Each time the traction control switch is pressed, the TCS enabled/disabled status changes. When TCS is disabled, the electronic brake control module (EBCM) illuminates the traction off indicator by opening the service traction control signal circuit.

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 EBCM detects low voltage on the traction control switch signal circuit for 10 seconds.

Action Taken When the DTC Sets

The EBCM defaults the traction control system status to Enabled.

Conditions for Clearing the DTC

The conditions for setting the DTC are no longer present and you use the scan tool Clear DTCs function.

Diagnostic Aids

Thoroughly inspect connections or circuitry that may cause an intermittent malfunction. Refer to the following:

    •  Testing for Electrical Intermittents
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs
    •  Connector Repairs

Step

Action

Yes

No

Schematic Reference: Antilock Brake System Schematics

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle

2

  1. Use a scan tool in order to clear the DTCs.
  2. Turn OFF the ignition for 5 seconds.
  3. Turn ON the ignition for 20 seconds.

Does the DTC set?

Go to Step 3

Go to Diagnostic Aids

3

  1. Turn OFF the ignition.
  2. Disconnect the traction control switch harness connector. Refer to Electronic Traction Control Switch Replacement
  3. Turn ON the ignition for 20 seconds.

Does the DTC set?

Go to Step 4

Go to Step 6

4

  1. Disconnect the electronic brake control module (EBCM) harness connector.
  2. Test the traction control switch signal circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 7

Go to Step 5

5

Replace the EBCM. Refer to Control Module References for replacement, setup, and programming.

Did you complete the replacement?

Go to Step 7

--

6

Replace the traction control switch. Refer to Electronic Traction Control Switch Replacement

Did you complete the replacement?

Go to Step 7

--

7

  1. Use the scan tool in order 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