Circuit/System Testing

WARNING: This page is about a different car, the 2008 Chevrolet Malibu Classic. However, it is still accessible from the selected car via links, so may be relevant.

IMPORTANT: It is recommend that Component Testing is performed before Circuit Testing when diagnosing wheel speed sensors.

Ignition OFF, disconnect the harness connector at the EBCM.
Ignition ON, test for less than 1 volt between the low reference circuit terminal of the appropriate sensor listed below and ground.
- LF Sensor circuit terminal 13
- RF Sensor circuit terminal 27
- LR Sensor circuit terminal 41
- RR Sensor circuit terminal 44
- If greater than the specified value, test the low reference circuit for a short to voltage. If the circuit tests normal, replace the EBCM.
Test for less than 1 volt between the signal circuit terminals of the appropriate sensor listed below and ground.
- LF Sensor circuit terminal 12
- RF Sensor circuit terminal 26
- LR Sensor circuit terminal 42
- RR Sensor circuit terminal 43
- If greater than 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 13
- RF Sensor circuit terminal 27
- LR Sensor circuit terminal 41
- RR Sensor circuit terminal 44
- If less than 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 12
- RF Sensor circuit terminal 26
- LR Sensor circuit terminal 42
- RR Sensor circuit terminal 43
- If less than 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.