Circuit Description
The TCS OFF Indicator is controlled by the electronic brake control module (EBCM) by sending a signal to the instrument panel cluster (IPC). It is turned on when the EBCM sets a DTC that turns on the TCS OFF indicator. It is also turned on or off when the Control Switch is pressed. The EBCM supplies 12 volts to the Traction Control Switch, when the TCS switch is depressed the EBCM sees the voltage go low, and that the TCS switch state has changed. When the EBCM 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
Thoroughly inspect the wiring and the connectors. An incomplete inspection of the wiring and the connectors may result in a misdiagnosis, causing a part replacement with the reappearance of the malfunction.
The following are possible causes of the malfunction:
| • | An open or high resistance in the ABS indicator control circuit |
| • | An open, high resistance or short to ground in the IPC ignition voltage circuit |
| • | An open or high resistance in the EBCM ground circuits |
| • | An internal EBCM malfunction |
| • | An internal IPC malfunction |
If an intermittent malfunction exists, refer to Testing for Intermittent Conditions and Poor Connections .
Test Description
The numbers below refer to the step numbers on the diagnostic table.
-
This step tests the operation of the Trac Off indicator lamp circuit.
-
This step tests the EBCM ABS off warning lamp circuit for an open or high resistance.
-
This step tests the IPC ignition voltage circuit for an open, high resistance or short to ground.
-
This step tests the EBCM ground circuits.
Step | Action | Value(s) | 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 | |
Does the TCS OFF indicator turn ON and OFF when commanded? | -- | Go to Step 9 | Go to Step 3 | |
3 | Tun ON the ignition and observe the Multi Function Display. Does the Multi Function Display indicate "System OK"? | -- | Go to Diagnostic Aids | Go to Step 4 |
4 |
Does the voltage measure as specified? | Battery Voltage | Go to Step 5 | Go to Step 6 |
Test the EBCM ABS OFF warning lamp circuit for an open or high resistance. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 11 | Go to Step 7 | |
Test the IPC ignition voltage circuit for an open, high resistance or short to ground. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 11 | Go to Step 8 | |
Test the electronic brake control module (EBCM) ground circuits for an open or high resistance. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 11 | Go to Step 10 | |
8 | Locate and repair the open, high resistance or short to ground in the ignition control relay circuits. Refer to Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 11 | -- |
9 | Replace the EBCM. Refer to Electronic Brake Control Module Replacement . Did you complete the replacement? | -- | Go to Step 11 | -- |
10 | Replace the IPC. Refer to Instrument Cluster Replacement . Did you complete the replacement? | -- | Go to Step 11 | -- |
11 |
Does the DTC reset? | -- | Go to Step 2 | System OK |
