Circuit/System Verification

WARNING: This page is about a different car, the 2017 Cadillac ATS. However, it is still accessible from the selected car via links, so may be relevant.

NOTE:

This vehicle has a capless fuel fill design that requires the use of CH-44284-2 Fuel Flapper Door Holder to hold the two flapper valves open.

Install this tool so that the raised rib nests just inside the flapper door outer lip. The flappers will hold it in place.
Be careful the force of the flapper doesn't push the tool back out.
Do not insert tool any further into the fuel neck or it may get stuck or fall into the lower fill tube.

Ignition ON.
Verify DTC P0449 is not set.
- If the DTC is set
  Refer to Diagnostic Trouble Code (DTC) List - Vehicle .
- If the DTC is not set
Ignition OFF, install the CH-44284-2 in the fuel fill neck. Ignition ON.
Verify the scan tool Fuel Tank Pressure Sensor voltage parameter is within 1.3-1.7 V.
- If not between the 1.3-1.7 V
  Refer to P0452, P0453 within DTC P0451-P0454 .
- If between the 1.3-1.7 V
Remove the CH-44284-2. Engine idling at operating temperature for 5 min,
Verify the scan tool Fuel Tank Pressure Sensor parameter does not increase to greater than 2.5 V when commanding the EVAP Purge Solenoid Valve to 50%.
- If greater than 2.5 V
  Refer to Circuit System Testing.
- If 2.5 V or less
Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
- If the DTC sets
  Refer to Circuit System Testing.
- If the DTC does not set
All OK.