Circuit/System Verification
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.
- 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.
- Ignition ON, command the engine controls (EC) ignition relay ON and OFF, with a scan tool, while observing the EC ignition relay coil control circuit status parameters listed below:
- EC Ignition Relay Ckt. Short Gnd Test Status
- EC Ignition Relay Ckt. Open Test Status
- EC Ignition Relay Ckt. Short Volts Test Status
Each parameter should display OK or Not Run in each commanded state
- Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.