Circuit Description
The electronic brake control module (EBCM) turns ON the vehicle stability control (VSC) indicator by closing the VSC indicator control circuit. The Antilock Brake System (ABS) indicator is connected to the GAUGE fuse. This circuit has power when the ignition switch is in the ON or START positions. When the ignition switch is turned to the ON position, the EBCM turns ON the VSC indicator for 3 seconds for a bulb check. If the EBCM detects a malfunction, the VSC indicator will stay ON to warn the driver that the VSC is disabled and needs service.
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:
| • | A short in the VSC indicator control circuit |
| • | An open, high resistance, or short in the ignition positive voltage circuit |
| • | An open or high resistance in the EBCM ground circuits |
| • | An internal EBCM 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 ignition positive voltage circuit for an open or short to ground.
This step tests the EBCM ground circuits for an open or high resistance.
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This step tests the VSC indicator control circuit for a short
Step | Action | 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 | |
2 | Inspect for poor connections at the harness connector of the electronic brake control module (EBCM). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs. Did you find and correct the condition? | Go to Step 9 | Go to Step 3 |
3 | Measure the battery voltage. Is the battery voltage as specified? | Go to Step 4 | |
Did you find and correct the condition? | Go to Step 9 | Go to Step 5 | |
5 |
Is the vehicle stability control (VSC) indicator ON? | Go to Step 6 | Go to Step 8 |
Test the VSC indicator control circuit for a short. Refer to Circuit Testing and Wiring Repairs. Did you find and correct the condition? | Go to Step 9 | Go to Step 7 | |
7 | Replace the instrument panel cluster assembly. Refer to Instrument Cluster Replacement. Did you complete the replacement? | Go to Step 9 | -- |
8 | Replace the brake pressure modulator valve (BPMV). Refer to Brake Pressure Modulator Valve Assembly Replacement. Is the repair complete? | Go to Step 9 | -- |
9 | Operate the system in order to verify the repair. Did you correct the condition? | System OK | Go to Step 2 |
