GM Service Manual Online
For 1990-2009 cars only

ORVR Fuel System


Object Number: 341647  Size: MF
(1)Fuel Tank Pressure Sensor
(2)Modular Fuel Sending Unit
(3)Check Valve
(4)Fuel Tank Filler Pipe
(5)Shut-Off Valve
(6)Fuel Tank
(7)EVAP Canister
(8)Service Port
(9)Canister Purge Valve
(10)Engine Control Module (ECM)
(11)Fuel Limiter Vent Valve and Rollover Valve

Important: Always start with the Powertrain On-Board Diagnostic (OBD) system check. This will reduce diagnostic time and prevent unnecessary parts replacement.

The enhanced evaporative emission (EVAP) control system diagnosis is covered in the following DTCs:

    •  DTC P0440 Evaporative Emission (EVAP) System
    •  DTC P0443 Evaporative Emission (EVAP) Purge Solenoid Control Circuit
    •  DTC P0446 Evaporative Emission (EVAP) Vent Solenoid Control Circuit
    •  DTC P0450 Fuel Tank Pressure Sensor Circuit
    •  DTC P0455 Evaporative Emission (EVAP) System Leak Detected

System Inspection and Cleaning

Important: Disconnect the hoses and pipes from the EVAP canister and the EVAP purge valve before applying compressed nitrogen.

Disconnect the vacuum source line at the purge valve and the manifold vacuum source. Remove the EVAP purge valve. Disconnect the purge line at the canister. Inspect all of the hoses, pipes, and components for contamination. If a component is malfunctioning due to contamination, the component must be replaced. Contamination of the hoses and pipes should be blown out with compressed nitrogen from the J 41413 EVAP pressure/purge cart.

If carbon contamination of the system is evident, replace EVAP canister and fuel tank.