EI07238 -- Fuel Cap May Not Seal, MIL/SES Light Illuminated with DTC P0442 - Evaporative Emission (EVAP) System Small Leak Detected and/or P0455 - Evaporative Emission (EVAP) System Large Leak Detected
Models: 2005-2007 Cadillac XLR, XLR-V
2005-2007 Chevrolet Corvette
Attention:
Proceed with this bulletin ONLY if the customer has commented about this concern AND the EI number is listed in GMVIS. If the customer has not commented about this condition or the EI does not show in GMVIS, disregard the bulletin and proceed with diagnostics found in the published Service Information. THIS IS NOT A RECALL--refer to Service Bulletin 04-00-89-053B for more detail on the use of Engineering Information Bulletins.
This bulletin is being revised to add additional EVAP test information. Please discard Corporate Bulletin Number 07-06-04-022D (Section 06 -- Engine/Propulsion System).
ConditionSome customers may comment on a Service Engine Soon (SES) Light illuminated on the IP cluster and the fuel cap does not seal or tighten. Technicians may find DTC P0442 and/or P0455 set.
What Action to Take
GM Engineering is attempting to determine the root cause for fuel caps not sealing and/or setting codes P0442 or P0455. GM Engineering has a need to obtain information first hand from the dealer technician during diagnosis and before repair.
As a result, this information will be used by engineering to "root cause" the customer's concern and develop/validate a field fix. Please follow the instructions below regarding the requested information.
InstructionsImportant:
If a vehicle is encountered with the above concern, complete the following steps; making sure all the information is documented on the Repair Order.
Verify that the VIN and mileage is accurate.
Accurately document the customers concern. If the SES light is illuminated, record the Diagnostic Trouble Codes (DTC) using a Tech 2®.
Important: DO NOT use fuel tank filler pipe/neck test adapters, fuel cap testers or smog machines when trying to root cause the EVAP leak.
Perform the EVAP Smoke Test using the service port at the engine side ONLY. The fuel cap needs to be on the fuel tank filler pipe/neck when performing the EVAP Smoke Test.
• If DTC P0442 - Evaporative Emission (EVAP) System Small Leak Detected is stored, proceed to diagnosis DTC P0442 in SI.
• If DTC P0455 - Evaporative Emission (EVAP) System Large Leak Detected is stored, proceed to diagnosis DTC P0455 in SI.
• If diagnostics lead to repair other components not related to the fuel tank filler pipe neck or fuel cap, repair accordingly and disregard this bulletin.
If the diagnostics lead to a leak at the fuel tank filler pipe neck or the fuel cap area, inspect for the following conditions:
• Inspect the condition of the fuel cap by looking for small cracks or any damaged components.
• Inspect the fuel cap seal for distortion or cuts.
• Inspect the fuel filler neck sealing surface for gouges or dents produced accidentally by a fuel nozzle.