Circuit/System Testing

It is recommended that Component Testing is performed before Circuit Testing when diagnosing wheel speed sensors.

1. Ignition OFF, disconnect the harness connector at the suspect wheel speed sensor.
2. Ignition ON, test for ignition voltage between the signal circuit terminal A and ground.
   • If not the specified value, test the signal circuit for a short to ground or open/high resistance. If the circuit tests normal, replace the EBCM.
3. Test for ignition voltage between the signal circuit terminal A and the low reference circuit terminal B.
   • If not the specified value, test the signal circuit for an open/high resistance. If the circuit tests normal, replace the EBCM.
4. Disconnect the harness connector at the EBCM.
5. Test for infinite resistance between the low reference circuit terminal B and ground.
   • If not the specified value, test the low reference circuit for a short to ground.
6. If all circuits test normal, test or replace the wheel speed sensor.