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.

Conditions for Running the DTC

    • The ignition is ON.
    • The engine is running at a rate greater than 450 RPM.

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

If equipped, the following actions occur:

    • The EBCM disables the TCS.
    • The traction off indicator turns ON.

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

Test Description

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

  1. This step tests the traction control switch circuitry. If the fuse opens when you perform this test, the traction control switch signal circuit is shorted to ground.

Step

Action

Yes

No

Schematic Reference: Antilock Brake System Schematics

Connector End View Reference: Antilock Brake System Connector End Views

1

Did you perform the antilock brake system (ABS) Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - ABS

2

  1. Use a scan tool in order to clear the DTCs.
  2. Turn OFF the ignition for 5 seconds.
  3. Start the engine and allow the engine to run for at least 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.
  4. Connect a test lamp between the ignition 1 voltage circuit and a good ground.

Does the test lamp illuminate?

Go to Step 4

Go to Step 8

4

  1. Use the scan tool in order to clear the DTCs.
  2. Turn OFF the ignition.
  3. Connect a fused jumper wire between the ignition 1 voltage circuit and the traction control switch signal circuit at the traction control switch harness connector.
  4. Start the engine and allow the engine to run for at least 20 seconds.

Does the DTC set?

Go to Step 5

Go to Step 9

5

Test the traction control switch signal circuit for an open or a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 11

Go to Step 6

6

Inspect for poor connections at the harness connector of the electronic brake control module (EBCM). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 11

Go to Step 7

7

Important: Following EBCM replacement, use the scan tool to perform the Tire Size Calibration procedure.

Replace the EBCM. Refer to Electronic Brake Control Module Replacement .

Did you complete the replacement?

Go to Step 11

--

8

Repair the open in the ignition 1 voltage circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 11

--

9

Inspect for poor connections at the harness connector of the traction control switch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 11

Go to Step 10

10

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

Did you complete the replacement?

Go to Step 11

--

11

  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