Circuit Description
The TCS OFF Indicator is controlled by the EBCM by sending class 2 messages 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 Electronic Brake Control Module (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
| • | 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 Inducing Intermittent Fault Conditions in Wiring Systems for further diagnosis. |
Test Description
The number(s) below refer to the step number(s) on the diagnostic table.
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Checks if EBCM is receiving a Traction Control Switch message from the switch.
-
Checks if the scan tool can turn on and off all the indicator lamps in the instrument cluster.
-
Checks if the EBCM or Traction Control Switch is at fault.
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? | -- | ||
Does the switch status change from pressed to released as the TCS switch is pressed and released? | -- | |||
Does the TCS OFF indicator turn on then off? | -- | |||
4 |
Is the Instrument Cluster replacement complete? | -- | Go to Step Diagnostic System Check - ABS | -- |
Does the TCS Switch status read released? | -- | |||
6 | Replace the Traction Control Switch. Refer to Electronic Traction Control Switch Replacement Is the replacement complete? | -- | -- | |
7 |
Is the resistance within the range specified in the value(s) column? | OL (Infinite) | ||
8 | Repair CKT 1571 for a short to ground. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | -- | |
9 | Replace the EBCM. Refer to Electronic Brake Control Module Replacement Is the replacement complete? | -- | -- | |
