GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The Traction Off indicator is controlled by the instrument cluster via serial data messages from the EBCM. When the body control module sees the traction control switch input grounded through the momentary traction control switch, it sends a serial data message to the EBCM that tells the EBCM that the traction control switch has been pressed. The EBCM then disables traction control and sends a serial data message to the instrument cluster to turn the Traction Off indicator ON. Each time the ignition is cycled from OFF to ON, the traction control system is enabled.

The following conditions will cause the Traction Off indicator to illuminate:

    • The EBCM has disabled the TCS due to a DTC.
    • The driver manually disabling the TCS via the traction control switch.
    • The instrument cluster bulb check. When the ignition switch is turned to ON, the Traction Off indicator will turn on for approximately 3 seconds and then turn OFF.

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. Use the scan tool to check the normal state of the Traction Off indicator control.

  2. Ensures that the instrument cluster can operate the Traction Off indicator.

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 in Vehicle DTC Information

2

  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. With a scan tool, observe the ETS Warning Lamp parameter in the enhanced traction system (ETS) data list.

Does the scan tool display Off?

Go to Step 3

Go to Step 4

3

  1. Turn OFF the ignition.
  2. Turn ON the ignition, with the engine OFF.
  3. Observe the Traction Off indicator on the instrument panel cluster (IPC) during the bulb check.

Does the Traction Off indicator illuminate during the bulb check and then turn OFF?

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step 5

4

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 8

Go to Step 6

5

Inspect for poor connections at the harness connector of the IPC. 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 8

Go to Step 7

6

Replace the EBCM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming.

Did you complete the repair?

Go to Step 8

--

7

Replace the IPC. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming.

Did you complete the repair?

Go to Step 8

--

8

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2