Circuit Description
The ASR 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 ASR OFF indicator. It is also turned on or off when the Accelerator Slip Regulation (ASR) Switch is pressed. The Electronic Brake Control Module (EBCM) supplies 12 volts to the ASR Switch, when the ASR switch is depressed the EBCM sees the voltage go low, and that the ASR switch state has changed. When the EBCM receives that a switch state has changed it turns on or off the ASR and sends a message to the IPC to turn on or off the ASR 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 System 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 ASR Switch message from the switch.
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Checks if the scan tool can turn on and off all the indicator lamps in the instrument cluster.
-
Checks if the EBCM or ASR Switch is at fault.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
Schematic Reference: Antilock Brake System Schematics | ||||
1 | Did you perform the Diagnostic System Check? | -- | Go to Step 2 | |
Does the switch status change from pressed to released as the ASR switch is pressed and released? | -- | Go to Step 3 | Go to Step 5 | |
Does the ASR OFF indicator turn on then off? | -- | Go to Step 9 | Go to Step 4 | |
4 |
Is the instrument cluster replacement complete? | -- | -- | |
Does the TCS switch status read released? | -- | Go to Step 6 | Go to Step 7 | |
6 | Replace the ASR 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) | Go to Step 9 | Go to Step 8 |
8 | Repair the traction control switch signal circuit 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? | -- | -- | |
