Circuit/System Testing
WARNING: This page is about a different car, the 2008 GMC Yukon and 2008 Chevrolet Tahoe. However, it is still accessible from the selected car via links, so may be relevant.
- Ignition OFF, open the hood to disable the Auto-Stop function. Refer to Hybrid Modes of Operation Description .
- Ignition ON, verify the scan tool hood position parameter displays OPEN.
- If the hood position does not display OPEN, refer to Diagnostic Trouble Code (DTC) List - Vehicle for DTC P254F.
- With the ignition OFF, disconnect the harness connector at the FPCM.
- With the ignition ON, engine OFF, probe the control circuit of the fuel pump control module terminal 13 with a test lamp that is connected to a good ground. Command the fuel pump ON and OFF with a scan tool. The test lamp should turn ON and OFF with each command.
- If the test lamp does not turn ON and OFF, test for an open, high resistance, or a short to ground in the fuel pump relay control circuit, an intermittent or a poor connection at the engine control module (ECM). If the circuit tests normal, replace the control module.
- If the test lamp remains illuminated with each command, test for a short to voltage in the control circuit of the fuel pump relay or an intermittent or a poor connection at the ECM. If the circuit tests normal, replace the control module.
- If all circuits test normal, replace the FPCM.