Diagnostic Instructions
| • | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
| • | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
| • | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
Diagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
Traction Control Active Signal | 1 | 1 | 2 | -- |
1. Circuit Inoperative 2. Circuit Always ON | ||||
Circuit/System Description
The ignition 3 voltage circuit supplies a momentary application of ground to the traction control switch. The electronic brake control module (EBCM) illuminates the Traction OFF indicator by applying voltage to the service traction control signal circuit.
Diagnostic Aids
| • | Thoroughly inspect connections or circuitry that may cause an intermittent malfunction. |
| • | For all traction control DTC resets, verify EC 30 ECU configuration by turning the ignition ON and monitoring the ECU LEDs. |
Reference Information
Schematic Reference
Air Antilock Brake System Schematics
Connector End View Reference
Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References for EBCM
Circuit/System Verification
Ignition ON, observe the scan tool Traction OFF parameter while pressing/depressing the traction control switch. The reading should change between OFF/ON and ON/OFF traction off switch command value.
Circuit/System Testing
- Ignition OFF, disconnect the Traction OFF harness connector at the traction control switch.
- Igniton ON, verify that a test lamp illuminates between the EBCM traction control active signal circuit terminal 1 and ground.
- Verify the scan tool Traction OFF Command parameter is OFF.
- Install a 3 A fused jumper wire between the traction control active signal circuit terminal 1 and the traction control switch ignition 1 voltage circuit terminal 3. Verify the scan tool Traction OFF Command parameter is ON.
- If all circuits test normal, test or replace the traction control switch.
| ⇒ | If the test lamp does not illuminate, test the traction control active signal circuit for a short to ground or an open/high resistance. If the circuit tests normal and the ignition 3 circuit breaker is open, test the traction control active signal circuit terminal 1 for a short to ground. |
| ⇒ | If not the specified value, test the traction control active signal circuit terminal 1 for a short to voltage. If the circuit tests normal, replace the EBCM. |
| ⇒ | If not the specified value, test the traction control active signal circuit for an open/high resistance. If the circuit tests normal, replace the EBCM. |
Component Testing
- Ignition OFF, disconnect the harness connector at the traction control switch.
- Test for infinite resistance between the traction control active signal terminal 1 and the low traction indicator control terminal 13 with the switch in the open position.
- Test for less than 2 ohms between the traction control active signal terminal 1 and the low traction indicator control terminal 13 with the traction off switch in the closed position.
- Test for infinite resistance between each terminal and the traction control switch housing/case.
| ⇒ | If not the specified value, replace the traction control switch. |
| ⇒ | If greater than the specified range, replace the traction control switch. |
| ⇒ | If not the specified value, replace the traction control switch. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for EBCM setup, replacement, and programming |
Repair Verification
- Ignition OFF, wait for 5 seconds
- Ignition ON, observe the Instrument Panel Cluster Low Traction indicator. The Low Traction Indicator should illuminate for 3 seconds and go OFF.
