Circuit/System Testing
WARNING: This page is about a different car, the 2007 GMC Sierra and 2007 Chevrolet Silverado. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
A condition may result in a stored history DTC C0055, check the replicated transmission output speed signal circuit for damaged wires, missing pulses or electrical noise that may be passed to 128 K pulses/mile engine speed signal.
- Ignition OFF disconnect the harness connector at the EBCM.
- Ignition ON, test for greater than 10 V between the signal circuit terminal 20 and ground.
- If less than the 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 appropriate harness connector listed below at the ECM:
- X1 (Gas)
- X2 (Diesel)
- Ignition OFF, disconnect the appropriate harness connector listed below at the ECM:
- Terminal 57 X1 (Gas)
- Terminal 54 X2 (Diesel)
- If the test lamp illuminates, test the signal circuit for a short to voltage.
- If all circuits test normal, replace the EBCM.