Circuit/System Testing

Turn ON the ignition with the engine OFF. Place the gear selector of the transmission in reverse. The reverse lamps should illuminate.
- If the reverse lamps do not illuminate, go to Diagnostic Aids or Symptoms - Lighting .
Turn the ignition OFF. Disconnect the EBCM harness connector. Connect a test lamp between the backup lamp supply voltage circuit of the harness connector and ground. Turn the ignition ON and place the gear selector of the transmission in reverse.
- If the test lamp does not illuminate, repair open in the backup lamp supply voltage circuit between the splice and the EBCM connector.

If the test lamp illuminates, replace the EBCM/brake pressure modulator valve (BPMV) assembly.