Circuit/System Testing
WARNING: This page is about a different car, the 2010 GMC Sierra and 2010 Chevrolet Silverado. However, it is still accessible from the selected car via links, so may be relevant.
- Verify that no DTCs are set in the ECM or TCM.
- If DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle .
- Ignition OFF, disconnect the harness connector at the EBCM.
- Ignition ON, test for greater than 10 V between the signal circuit terminal 31 and ground.
- If less than specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the ECM.
- Ignition OFF, disconnect the X 1 harness connector at the ECM.
- Ignition ON, verify that a test lamp does not illuminate between the signal circuit terminal 50 and ground.
- If the test lamp illuminates, test the signal circuit for a short to voltage.
- If the circuit tests normal, replace the EBCM.