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 RIM 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 on the Traction Off indicator on the instrument panel. Each time the ignition is cycled from OFF to ON, the traction control system is enabled.

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 control.

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

Step

Action

Yes

No

Schematic Reference: Antilock Brake System Schematics

Connector End View Reference: Antilock Brake System Connector End Views , Instrument Panel, Gages, and Console Connector End Views in Instrument Panel, Gages, and Console

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 TCS Off Indicator parameter in the TCS data list.

Does the scan tool display Off?

Go to Step 3

Go to Step 8

3

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

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

Go to Step 4

Go to Step 9

4

  1. Turn OFF the ignition.
  2. Disconnect the traction control switch connector.
  3. Connect a 3 amp fused jumper from the signal circuit of the traction control switch to the ground circuit of the traction control switch.
  4. Turn ON the ignition, with the engine OFF.
  5. With a scan tool, observe the TCS Switch State parameter.

Does the scan tool display pressed?

Go to Step 7

Go to Step 5

5

Test the signal circuit of the traction control switch for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 13

Go to Step 6

6

Test the ground circuit of the traction control switch for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 13

Go to Step 7

7

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 13

Go to Step 10

8

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 13

Go to Step 11

9

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 13

Go to Step 12

10

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

Did you complete the replacement?

Go to Step 13

--

11

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

Did you complete the replacement?

Go to Step 13

--

12

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

Did you complete the replacement?

Go to Step 13

--

13

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2