Circuit Description
The ABS indicator is controlled by the EBCM. The EBCM supplies the ground to the ABS indicator circuit to turn the indicator on. When the ABS indicator circuit is not grounded at the EBCM, the ABS indicator remains off. The EBCM harness connector contains a shorting bar for the ABS indicator circuit. When the EBCM connector is disconnected from the EBCM, the shorting bar shorts the ABS indicator terminal to ground turning on the indicator.
Diagnostic Aids
If the EBCM harness connector is not securely connected to the EBCM, the shorting bar in the harness connector may turn on the ABS indicator. Make sure the EBCM harness connector is securely connected to the EBCM.
| • | 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 for further diagnosis. |
Test Description
The number(s) below refer to the step number(s) on the diagnostic table.
-
This step checks for an internal EBCM short. You must install the pinout box and cable adapter to the harness connector at this point to prevent the shorting bar in the harness connector from grounding the circuit and turning on the indicator.
-
This step checks for a short to ground in the ABS indicator circuit.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
Schematic Reference: Antilock Brake System Schematics | ||||
1 | Did you perform the Diagnostic System Check? | -- | Go to Step 2 | |
Is the ABS Indicator off? | -- | Go to Step 3 | Go to Step 4 | |
3 | Replace the EBCM. Refer to Electronic Brake Control Module Replacement . Is the replacement complete? | -- | Go to Step 7 | -- |
Is the resistance within the range specified in the value(s) column? | OL | Go to Step 6 | Go to Step 5 | |
5 | Repair the ABS indicator circuit for a short to ground. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | Go to Step 7 | -- |
6 | Suspect the instrument cluster. Refer to Diagnostic System Check - Instrument Cluster in Instrument Panel, Gauges and Console. 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 |
