ABS Indicator Always On Domestic
Circuit Description
The EBCM illuminates the ABS indicator by supplying ground to the lamp . When the ABS indicator is commanded ON, the feedback voltage to the EBCM from the ABS indicator failure control circuit is low.
Diagnostic Aids
Thoroughly inspect connections or circuitry that may cause an intermittent malfunction. Refer to the following:
Test Description
The numbers below refer to the step numbers on the diagnostic table.
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This step tests if the EBCM is applying ground to the ABS indicator lamp.
-
This step tests the ABS indicator failure control circuit for a short to ground by substituting the instrument panel cluster and the ABS indicator lamp with a test lamp while leaving the EBCM disconnected.
Step | Action | Yes | No |
|---|---|---|---|
Schematic Reference: Antilock Brake System Schematics | |||
1 | Did you perform the ABS Diagnostic System Check? | Go to Step 2 | |
2 |
Does the ABS indicator illuminate for 2 seconds and then turn OFF? | Go to Diagnostic Aids | Go to Step 3 |
Does the ABS indicator illuminate? | Go to Step 4 | Go to Step 7 | |
Does the test lamp illuminate? | Go to Step 5 | Go to Step 6 | |
5 | Repair the short to ground in the ABS indicator failure control circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 8 | -- |
6 | Replace the instrument panel cluster. Refer to Instrument Cluster Replacement in Instrument Panel, Gages, and Console. Did you complete the replacement? | Go to Step 8 | -- |
7 |
Important: Following EBCM replacement, use the scan tool to perform the Tire Size Calibration procedure. Replace the EBCM. Refer to Electronic Brake Control Module Replacement . Did you complete the replacement? | Go to Step 8 | -- |
8 |
Does the ABS indicator illuminate for 2 seconds and then turn OFF? | System OK | Go to Step 3 |
ABS Indicator Always On Export
Circuit Description
The EBCM illuminates the ABS indicator by supplying ground to the lamp. When the ABS indicator is commanded ON, the feedback voltage to the EBCM from the ABS indicator failure control circuit is low. The ABS indicator also illuminates if the ground circuit between EBCM and the electronic brake control lamp relay is open.
Diagnostic Aids
Thoroughly inspect connections or circuitry that may cause an intermittent malfunction. Refer to the following:
Test Description
The numbers below refer to the step numbers on the diagnostic table.
-
A malfunction which illuminates the red brake warning indicator also illuminates the ABS indicator.
-
This step tests if the electronic brake control lamp relay is applying ground to the ABS indicator lamp.
-
This step tests if the EBCM is applying ground to the ABS indicator lamp.
-
This step tests the ABS indicator failure control circuit for a short to ground by substituting the instrument panel cluster and the ABS indicator lamp with a test lamp while leaving the EBCM disconnected.
Step | Action | Yes | No |
|---|---|---|---|
Schematic Reference: Antilock Brake System Schematics | |||
1 | Did you perform the ABS Diagnostic System Check? | Go to Step 2 | |
2 |
Does the ABS indicator illuminate for 2 seconds and then turn OFF? | Go to Diagnostic Aids | Go to Step 3 |
Is the brake warning indicator also always ON? | Go to Brake Warning Indicator Always On in Hydraulic Brakes | Go to Step 4 | |
Does the ABS indicator illuminate for 2 seconds and then turn OFF? | Go to Step 7 | Go to Step 5 | |
Does the ABS indicator illuminate? | Go to Step 6 | Go to Step 16 | |
Does the test lamp illuminate? | Go to Step 8 | Go to Step 14 | |
7 | Connect a test lamp between the ignition 3 voltage circuit in the underhood fuse-relay center and a good ground. Does the test lamp illuminate? | Go to Step 10 | Go to Step 9 |
8 | Repair the short to ground in the ABS indicator failure control circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 17 | -- |
9 | Repair the open in the ignition 3 voltage circuit. Refer to Wiring Repairs in Wiring systems. Did you complete the repair? | Go to Step 17 | -- |
10 | Connect a test lamp between battery positive voltage and the ground circuit of the electronic brake control lamp relay coil. Does the test lamp illuminate? | Go to Step 12 | Go to Step 11 |
11 |
Did you find and correct the condition? | Go to Step 17 | Go to Step 15 |
12 | Inspect for poor connections at the electronic brake control lamp relay. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 17 | Go to Step 13 |
13 | Replace the electronic brake control lamp relay. Did you complete the replacement? | Go to Step 17 | -- |
14 | Replace the instrument panel cluster. Refer to Instrument Cluster Replacement in Instrument Panel, Gages, and Console. Did you complete the replacement? | Go to Step 17 | -- |
15 | Inspect for poor connections at the harness connector of the EBCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 17 | Go to Step 16 |
16 |
Important: Following EBCM replacement, use the scan tool to perform the Tire Size Calibration procedure. Replace the EBCM. Refer to Electronic Brake Control Module Replacement . Did you complete the replacement? | Go to Step 17 | -- |
17 |
Does the ABS indicator illuminate for 2 seconds and then turn OFF? | System OK | Go to Step 3 |
