Circuit Description
The electronic brake control module (EBCM) turns ON the antilock brake system (ABS) indicator by opening the ABS indicator control circuit. The 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 ABS indicator for 3 seconds for a bulb check. If the EBCM detects a malfunction, the ABS indicator will stay ON to warn the driver that the ABS 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:
| • | An open in the ABS Indicator Control circuit. |
| • | An internal EBCM malfunction. |
| • | A malfunctioning Instrument Cluster Panel Assembly. |
If an intermittent malfunction exists, refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.
Test Description
The number(s) below refer to the step number(s) on the diagnostic table.
Step | Action | Yes | No |
|---|---|---|---|
Schematic Reference: Antilock Brake System Schematics Connector End View Reference: Antilock Brake System Connector End Views | |||
1 | Did you perform A Diagnostic System Check - ABS? | Go to Step 2 | |
2 | Do any of the other instrument cluster indicators or gages function? | Go to Step 3 | Go to Gages Inoperative - All in Instrument Panel, Gages, and Console |
Does the ABS indicator turn ON? | Go to Step 6 | Go to Step 4 | |
4 | Test the ABS indicator control circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 7 | Go to Step 5 |
5 | Replace the instrument panel cluster assembly. Refer to Instrument Cluster Replacement in Instrument Panel, Gages, and Console. Did you complete the replacement? | Go to Step 7 | -- |
6 | Replace the brake pressure modulator valve (BPMV). Refer to Brake Pressure Modulator Valve Assembly Replacement . Is the repair complete? | Go to Step 7 | -- |
7 | Operate the system in order to verify the repair. Did you correct the condition? | System OK | Go to Step 2 |
