For 1990-2009 cars

### Circuit Description

The traction control system (TCS) warning indicator is controlled by the electronic brake control module (EBCM). The EBCM supplies the ground to the TCS warning indicator control circuit to turn the indicator on. When the TCS warning indicator control circuit is not grounded at the EBCM, the TCS warning indicator remains off. When the EBCM sees the traction control switch voltage go low, it turns the TCS warning indicator on and disables traction control.

### Diagnostic Aids

• | It is very important that a thorough inspection of the wiring and connectors be performed. Failure to carefully and fully inspect wiring and connectors may result in misdiagnosis, causing part replacement with reappearance of the malfunction.

• | Thoroughly inspect any circuitry that may be causing the complaint for the following conditions:

- | Backed out terminals

- | Improper mating

- | Broken locks

- | Improperly formed or damaged terminals

- | Poor terminal-to-wiring connections

- | Physical damage to the wiring harness

• | The following conditions may cause an intermittent malfunction:

- | A poor connection

- | Rubbed-through wire insulation

- | A broken wire inside the insulation

• | If an intermittent malfunction exists refer to General Electrical Diagnosis for further diagnosis.

### Test Description

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

1. This step tests for an internal EBCM malfunction.

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 Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle
2 | Do any of the other instrument cluster indicators or gages function? | Go to Step 3 | Go to Symptoms - Instrument Panel, Gages and Console
3 |

1. Turn OFF the ignition.
2. Disconnect the electronic brake control module (EBCM) electrical connector.
3. Connect a 3-amp fused jumper wire between the traction control system (TCS) warning indicator control circuit and ground.
4. Turn ON the ignition, with the engine OFF.

Is the TCS warning indicator turn ON?

Go to Step 6

Go to Step 4

4 | Test the TCS warning indicator control circuit for an open or high resistance. 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 instrument cluster. Refer to Instrument Cluster Replacement . Did you complete the replacement? | Go to Step 7 | --
6 | Replace the EBCM. Refer to Brake Pressure Modulator Valve Assembly Replacement . Did you complete the replacement? | Go to Step 7 | --
7 | Operate the system in order to verify the repair. Did you complete the repair? | System OK | Go to Step 2