GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The Traction Control indicator is controlled by the instrument cluster (IPC) via serial data messages from the EBCM. The EBCM send a serial data message to the IPC to illuminate the Traction Control indicator when the EBCM has disabled TCS due to a DTC. The Traction Control indicator will also turn ON during the instrument cluster bulb check. When the ignition switch is turned to ON, the Traction Control 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 in order to verify the normal state of the Traction Control indicator control.

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

Step

Action

Yes

No

Schematic Reference: Antilock Brake System Schematics

1

Did you perform the ABS Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - ABS

2

Inspect the EBCM ground, making sure the ground is clean and torqued to the proper specification. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 9

Go to Step 3

3

  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. With the scan tool, observe the TCS Warning Lamp parameter in the Delco/Bosch ABS/TCS ICCS (if equipped) data list.

Does the scan tool display Off?

Go to Step 4

Go to Step 5

4

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

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

Go to Step 5

Go to Step 6

5

Inspect for poor connections at the harness connector of the 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 9

Go to Step 7

6

Inspect for poor connections at the harness connector of the instrument cluster (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 9

Go to Step 8

7

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

Did you complete the repair?

Go to Step 9

--

8

Replace the instrument cluster (IPC). Refer to Instrument Cluster Replacement in Instrument Panel, Gauges and Console.

Did you complete the repair?

Go to Step 9

--

9

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2