Circuit Description
The ignition 1 voltage circuit supplies power to the LOW TRACTION indicator. The EBCM controls the LOW TRACTION indicator illumination by supplying ground to the lamp.
Diagnostic Aids
The traction control system can be controlled by the operator as follows:
| • | Through operation of the traction assist switch on the instrument panel. |
| • | Through programming of the traction control system's 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) will differ. For a more detailed explanation of these operational characteristics, refer to "Traction Assist Indicator Lamps" in ABS Operation .
To determine the status of the traction control system when it is unknown if the system is operational, install a scan tool in the vehicle and select the following data list parameters:
| • | Traction Assist Enabled |
| • | Traction Off Lamp Command |
Press the traction assist switch and observe the scan tool to verify a change in the status of the data list parameters.
Test Description
The numbers below refer to the step numbers on the diagnostic table.
-
This step tests for power at the traction assist switch. The IGN1 fuse supplies power to the traction assist switch.
-
This step verifies that the EBCM is providing ground to the LOW TRACTION indicator.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
Schematic Reference: Antilock Brake System Schematics | ||||
1 | Did you perform A Diagnostic System Check? | -- | Go to Step 2 | Go to Diagnostic System Check |
2 | Use a 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? | -- | Go to Diagnostic Aids | Go to Step 3 |
Does the test lamp illuminate? | -- | Go to Step 4 | Go to Step 8 | |
Does the test lamp turn on and off with each command? | -- | Go to Step 6 | Go to Step 5 | |
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 assist 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 open 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 assist switch. Refer to Traction Assist Switch Replacement . Did you complete the replacement? | -- | Go to Step 11 | -- |
10 |
Important: 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 |
