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.

NOTE: On the scan tool, the powertrain relay is referred to as the EC ignition relay.

Ignition ON, observe the scan tool DTC information. Verify DTC P0685 or P0690 is not set.
- If a DTC is set, refer to Diagnostic Trouble Code (DTC) List - Vehicle for further diagnosis.
Ignition ON, engine OFF, observe the scan tool Ignition 1 Voltage signal and the EC Ignition Relay Feedback signal parameters. There should be no greater than 3 V difference between the 2 parameters.
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.