Circuit Description
The ignition 1 voltage circuit supplies 12 volts to the traction control switch. The EBCM illuminates the low traction indicator by applying ground to the traction control active signal circuit.
Diagnostic Aids
The traction control system can be controlled by the operator in the following ways:
| • | Through operation of the traction control switch. |
| • | Through programming of the traction control system automatic engagement feature. |
Depending on the programmed state, the operation of the traction control system, as well as the operation of the traction off and low traction indicators, differs. For a more detailed explanation of these operational characteristics, refer to Traction Control Indicator Lamps in ABS Description and Operation .
Observe the data list parameters listed below in order to determine the status of the traction control system when it is unknown if the system is operational.
| • | Traction Control Enabled |
| • | Traction Off Lamp Command |
Press the traction control switch and observe the scan tool in order to verify a change in the status of the data list parameters.
Thoroughly inspect connections or circuitry that may cause an intermittent malfunction. Refer to Testing for Intermittent Conditions and Poor Connections , Wiring Repairs and Connector Repairs in Wiring Systems.
Test Description
The numbers below refer to the step numbers on the diagnostic table.
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This step verifies the ignition 1 voltage circuit can supply adequate power to the traction control switch.
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This step verifies the EBCM is applying ground to the low traction indicator.
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The EBCM may be damaged if the traction control active signal circuit is shorted to voltage.
Step | Action | Yes | No |
|---|---|---|---|
Schematic Reference: Antilock Brake System Schematics | |||
1 | Did you perform A Diagnostic System Check? | Go to Step 2 | |
2 |
Does the low traction indicator turn ON and OFF with each command? | Go to Diagnostic Aids | Go to Step 3 |
|
Important: Do not disconnect the traction control switch harness connector during this step.
Does the test lamp illuminate? | Go to Step 4 | Go to Step 8 | |
|
Important: Do not disconnect the traction control switch harness connector during this step.
Does the test lamp turn ON and OFF with each command? | Go to Step 6 | Go to Step 5 | |
Test the traction control active signal circuit for a short to voltage or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 11 | Go to Step 7 | |
6 | Inspect for poor connections at the traction control switch. 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 11 | Go to Step 9 |
7 | 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 11 | Go to Step 10 |
8 | Repair the high resistance in the ignition 1 voltage circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 11 | -- |
9 | Replace the traction control switch. Refer to Electronic Traction Control Switch Replacement . Did you complete the replacement? | Go to Step 11 | -- |
10 |
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 11 | -- |
11 | Use the scan tool in order to command the Low Trac Lamp On and Off. Does the low traction indicator turn ON and OFF with each command? | System OK | Go to Step 3 |
