Circuit/System Testing

IMPORTANT: It is recommended that Component Testing is performed before Circuit Testing when diagnosing wheel speed sensors because the module will default and does not supply voltage to the sensor when the DTC is set.
Performing Circuit Testing with EBCM connector disconnected and key on will cause U codes to set. Clear DTCs after performing the test.

Ignition OFF, disconnect the harness connector at the EBCM.
Ignition ON, test for 0 volts between the low reference circuit terminals of the appropriate sensor listed below and ground.
- LF Sensor circuit terminal A
- RF Sensor circuit terminal B
- If not the specified value, test the low reference circuit for a short to voltage. If the circuit tests normal, replace the EBCM.
Test for 0 volts between the signal circuit terminals of the appropriate sensor listed below and ground.
- LF Sensor circuit terminal B
- RF Sensor circuit terminal A
- If not the specified value, test the signal circuit for a short to voltage. If the circuit tests normal, replace the EBCM.
Ignition OFF, test for infinite resistance between the low reference terminals of the appropriate sensor listed below and ground.
- LF Sensor circuit terminal A
- RF Sensor circuit terminal B
- If not the specified value, test the low reference circuit for a short to ground. If the circuit tests normal, test or replace the wheel speed sensor.
Test for infinite resistance between the following signal circuit terminals of the appropriate sensor listed below and ground.
- LF Sensor circuit terminal B
- RF Sensor circuit terminal A
- If not the specified value, test the signal circuit for a short to ground. If the circuit tests normal, test or replace the wheel speed sensor.
If all circuits test normal, replace the EBCM.