Circuit Description
The Body Control Module (BCM) receives the input from the Traction Control Switch. The BCM then sends a class 2 message to the EBCM telling the EBCM the state of the switch. The BCM supplies voltage to the TCS switch and when the TCS switch is depressed the BCM sees the voltage go low and sends the EBCM the message that the TCS switch state has changed. When the EBCM receives the message from the BCM that the switch state has changed it turns on or off Traction Control and its TRAC 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 Testing for Intermittent Conditions and Poor Connections in Wiring Systems. |
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
DEFINITION: The TRAC OFF indicator does not come on when the Traction Control Switch is pressed to disable the Traction Control System. | ||||
1 | Did you perform the ABS Diagnostic System Check? | -- | ||
2 |
Does the TCS Switch state change properly as the switch is pressed and released? | -- | ||
3 | Using a scan tool in ABS/ETS/TCS read the TCS Switch Status as you press and release the TCS Switch. Does the TCS Switch state change properly as the switch is pressed and released? | -- | ||
4 | Replace the EBCM. Refer to Electronic Brake Control Module Replacement . Did you complete the repair? | -- | -- | |
5 |
Will the scan tool command the TRAC OFF indicator ON then OFF? | -- | ||
6 | Suspect the Instrument Panel Cluster. Refer to Instrument Cluster Diagnostic System Check in Instrument Panel, Gauges and Console. Did you complete the repair? | -- | -- | |
7 |
Does the TCS Switch status change with the jumper wire connected? | -- | ||
8 | Replace the Traction Control Switch. Refer to Traction Control Switch Replacement. Did you complete the repair? | -- | -- | |
9 |
Is the resistance within the range specified in the value(s) column? | 0-2 ohms | ||
10 | Repair the traction control ground circuit for an open or high resistance. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | -- | |
11 |
Is the resistance within the range specified in the value(s) column? | 0-2 ohms | ||
12 | Repair the traction control ground circuit for an open or high resistance. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | -- | |
13 | Suspect the Body Control Module. Refer to Body Control Module Diagnostic System Check in Body Control System. Did you complete the repair? | -- | -- | |
14 |
Does the DTC reset? | -- | System OK | |
