Circuit Description
The electronic brake control module (EBCM) controls the operation of the amber ABS indicator lamp by means of a ground circuit from the EBCM to the ABS lamp in the instrument panel cluster (IPC). The amber ABS lamp in the IPC receives power from fuse F1.
When the ignition switch is turned to the ON position, the EBCM turns ON the ABS indicator for 2 seconds for a bulb check. Whenever a malfunction is detected within the ABS system, the EBCM turns ON the ABS indicator, notifying the driver that ABS needs to be serviced.
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 to ground in the ABS indicator control circuit |
| • | A malfunctioning instrument panel cluster (IPC) |
| • | An internal EBCM malfunction |
If an intermittent malfunction exists, refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.
Test Description
The numbers below refer to the step numbers on the diagnostic table.
-
Determines whether there is a short to ground in the ABS indicator circuit or a malfunctioning EBCM.
Step | Action | Yes | No |
|---|---|---|---|
Schematic Reference: Antilock Brake System Schematics | |||
1 | Did you perform A Diagnostic System Check - ABS? | Go to Step 2 | |
Is the ABS indicator ON? | Go to Step 3 | Go to Step 5 | |
3 | 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 6 | Go to Step 4 |
4 | Replace the Instrument Cluster. Refer to Instrument Cluster Replacement in Instrument Panel, Gages, and Console. Did you complete the replacement? | Go to Step 6 | -- |
5 | Replace the EBCM. Refer to Electronic Brake Control Module Replacement . Is the repair complete? | Go to Step 6 | -- |
6 | Operate the system in order to verify the repair. Did you correct the condition? | System OK | Go to Step 2 |
