The ignition 3 voltage circuit supplies 12 volts to the traction control switch. The EBCM illuminates the traction off indicator by applying voltage to the service traction control signal circuit.
Thoroughly inspect connections or circuitry that may cause an intermittent malfunction. Refer to the following:
The numbers below refer to the step numbers on the diagnostic table.
This step tests for proper operation of the traction off indicator.
This step tests for proper operation of the traction switch.
This step tests for proper operation of the EBCM and harness containing the service traction control active signal circuit.
Step | Action | Yes | No |
---|---|---|---|
Schematic Reference: Air Antilock Brake System Schematics Connector End View Reference: Air Brake System Component Views | |||
1 | Did you perform the ABS Diagnostic System Check? | Go to Step 2 | |
Does the traction off indicator illuminate for 3 seconds and then turn OFF? | Go to Diagnostic Aids | Go to Step 3 | |
Does the test lamp illuminate for 3 seconds and then turn off? | Go to Step 4 | Go to Step 5 | |
4 | Replace the traction control switch. Refer to Air ABS Traction Control Switch Replacement . Did you complete the replacement? | Go to Step 8 | -- |
Does the test lamp illuminate? | Go to Step 6 | Go to Step 7 | |
6 | Repair short to voltage in the service traction control circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 8 | -- |
7 |
Important: Following EBCM replacement, perform the EBCM self-configuration procedure. Replace the EBCM. Refer to Electronic Brake Control Module Replacement . Did you complete the replacement? | Go to Step 8 | -- |
8 |
Does the low traction indicator illuminate for 3 seconds and then turn OFF? | System OK | Go to Step 3 |