For 1990-2009 cars
ABS Components
Without Traction Control

### Circuit Description

The TCS OFF Indicator is controlled by the EBTCM by sending class 2 messages to the Instrument Panel Cluster (IPC). It is turned on when the EBTCM sets a DTC that turns on the TCS OFF indicator. It is also turned on or off when the Traction Control Switch is pressed. The Electronic Brake Traction Control Module (EBTCM) supplies 12 volts to the Traction Control Switch, when the TCS switch is depressed the EBTCM sees the voltage go low, and that the TCS switch state has changed. When the EBTCM receives that a switch state has changed it turns on or off the Traction Control and sends a message to the IPC to turn on or off the TCS OFF indicator depending on its previous state.

### 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 Troubleshooting Procedures in Wiring Systems for further diagnosis.

### Test Description

The number(s) below refer to the step number(s) on the diagnostic table.

1. Checks if EBCM/EBTCM is receiving a Traction Control Switch message from the switch.

2. Checks if the scan tool can turn on and off all the indicator lamps in the instrument cluster.

3. Checks if the EBCM/EBTCM or Traction Control Switch is at fault.

#### TCS Off Indicator On with No DTC Set

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
DEFINITION: TCS Off indicator is on and traction control was not turned off. There are no DTC(s) set.
1 | Was the Diagnostic System Check performed? | -- | Go to Step 2 | Go to Diagnostic System Check - ABS
2 |

1. Turn the ignition switch to the RUN position, engine off.
2. Using a scan tool enter TCS Data List.
3. While monitoring the TCS On/Off switch status, press and release the TCS On/Off switch.

Does the switch status change from pressed to released as the TCS switch is pressed and released?

--

Go to Step 3

Go to Step 5

3 |

1. Using a scan tool in the instrument Pannel Cluster Special Function.
2. Go to WOW Instrument Panel in Output Control.
3. In the WOW mode you can turn on or off the instrument panel indicators.
4. All indicators will turn ON when commanded on.

Does the TCS OFF indicator turn on then off?

--

Go to Step 9

Go to Step 4

4 |

1. Disconnect the Instrument Cluster and connect a Test Light across the appropraiate power and ground terminals.
2. Test Light OFF, repair open in power or ground circuit to cluster.
3. Test Light ON, Check the connector for poor connection to Cluster.
4. If OK, replace the Instrument Cluster Instrument Cluster Replacement .

Is the Instrument Cluster replacement complete?

--

Go to Step Diagnostic System Check - ABS

--

5 |

1. Remove the Traction Control Switch and disconnect the connector. Refer to
2. Using a scan tool in ABS/TC Data List read the TCS Switch Status.
3. With the Traction Control Switch disconnected.

Does the TCS Switch status read released?

--

Go to Step 6

Go to Step 7

6 | Replace the Traction Control Switch. Refer to Electronic Traction Control Switch Replacement Is the replacement complete? | -- | Go to Diagnostic System Check - ABS | --
7 |

1. Turn the ignition switch to the OFF position.
2. Using J 39200 DMM, measure the resistance between the Traction Control Switch harness connector terminal E and a known good ground.

Is the resistance within the range specified in the value(s) column?

OL (Infinite)

Go to Step 9

Go to Step 8

8 | Repair CKT 1571 for a short to ground. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | Go to Diagnostic System Check - ABS | --
9 | Replace the EBTCM. Refer to Electronic Brake Control Module Replacement Is the replacement complete? | -- | Go to Diagnostic System Check - ABS | --