| Subject: | Diagnostic Aids for Diagnostic Trouble Codes P0440, P0455 and/or P0442 - Evaporative Emission (EVAP) System Leak |
| Models: | 2004 Buick Rainier |
| 2002-2004 Chevrolet TrailBlazer Models |
| 2002-2004 GMC Envoy Models |
| 2002-2004 Oldsmobile Bravada |
| with 83 Liter (22 Gallon) or 96 Liter (25 Gallon) Fuel Tanks |
This bulletin is being revised to remove the 2005 model year. Please discard Corporate Bulletin Number 05-06-04-014 (Section 06 - Engine/Propulsion System).
This bulletin is being published to aid technicians in the diagnosis of DTCs P0440, P0455 and/or P0442.
It is possible that a fracture as small as 0.508 mm (0.020 in) may be found in the fuel tank filler neck, causing a DTC P0440, P0455 and/or P0442 to set. Due to the location above the liquid fuel level, this small fracture will not cause a visible fluid
leak.
The technician should pay particular attention to the fuel tank filler neck area while performing the smoke test outlined in SI. Refer to the appropriate diagnostic information for P0440, P0455 and/or P0442 in SI.
When performing the smoke test outlined in SI, it may be necessary for the technician to manipulate the fuel tank filler neck in order to see smoke escaping from this minute fracture.
