I got code 10 pcm , P0455HC. Any clue would be appreciated.

 

Did you put gas in the car recently? Check the gas cap, clear all of the codes, and see if they come back.

 

Hav not gased up lately. It does seem like it (the cap) could be tighter. You think that is all it is?

 

Thank you. I checked it and it was loose. I think it may be toast. Thanks again.

 

Gotta love an easy fix!

 

Hopefully that will fix the problem. Looks like its a known problem that some GM gas caps may not properly seal themselves.

Here some information ( GM bulletin ) that was posted by forum sponsor Ken Fincher on the code.



EI07238-Fuel Cap May Not Seal, MIL/SES, DTC P0442 and/or P0455

--------------------------------------------------------------------------------
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 Buick Rainier
2005 Cadillac STS
2005–2006 Cadillac XLR, XLR-V
2004 Chevrolet Express
2005–2006 Chevrolet Corvette
2005 Chevrolet TrailBlazer, TrailBlazer EXT
2004 GMC Savana
2005 GMC Envoy, Envoy XL, Envoy XUV
2004–2005 Pontiac GTO
2004 Saturn ION
2004–2005 Saturn VUE
with 2.0L, 2.2L, 2.3L, 2.8L, 3.5L, 4.2L, 4.4L, 4.6L, 4.8L, 5.7L, 6.0L or 7.0L Engine
(VINs 4, A, D, E, F, G, S, U, V — RPOs LJ3, LC3, L61, LK9, LP9, L66, LH2, LL8, LR4, LS1, LS2, LS7)

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 04-00-89-053A for more detail on the use of Engineering
Information Bulletins.
________________________________________ ____________________________________
This bulletin is being revised to add additional models and model years and new contact information.
Please discard Corporate Bulletin Number 07-06-04-022A (Section 06 — Engine/Propulsion System)
________________________________________ ___________________________________
Condition
Some 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.

Instructions
Important: If a vehicle is encountered with the above concern, complete the following steps; making sure all the information is documented on the Repair
Order.

1. Verify that the VIN and mileage is accurate.
2. Accurately document the customers concern. If the SES light is illuminated, record the Diagnostic Trouble Codes (DTC) using a Tech 2®.
• 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.
3. 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.
4. Contact the appropriate GM Engineer once the vehicle has been diagnosed and before repairing the vehicle for further instructions.
Engineer Contact Information

Contact the appropriate GM Engineer from the list below before repairing the vehicle. GM Engineer Shannon Fahy may be used as a secondary contact. GM Engineering may visit dealerships near the Southwest Michigan area. In either case, you will receive a response back within 2 hours on what action to take the same day of your call (Eastern Daylight Time).

Warranty Information

Important: DO NOT use the labor operation listed below if engineering did not respond.

For vehicles repaired under engineering direction, use: Labor Operation Description Labor Time
L9714* Engineering Information-Fuel Cap and Filler Pipe – Replace
Corvette/XLR 1.8 hrs
Express/Savana 0.8 hr
GTO 0.7 hr
Envoy/Rainier/ TrailBlazer/VUE 1.0 hr
STS/ION 1.4 hrs
*This labor operation number is for bulletin use only. This number will not be published in the Labor Time Guide.

 

Thanks again. Sounds like you saved me some dough.

 

I just got the check engine myself and the only current code I found was P0442. I cleared it.

I gave the gas cap a few extra turns, it doesn't feel like it gets any tighter it just clicks.

Check Engine stayed on. Drove about 5 miles and it was still on. No new codes.

Do I need to disconnect the battery for a while (2-3 hours)?
I

 

Clear the codes via the DIC.

 

Doesnt seem like a GM only type problem. My friend has a 1996?? Ford Escort and his Engine light comes on ALL the time after pumping because the cap is loose. So he has to turn the cap like 900 times lol.

 

Gas caps are like $4-$5 if they are non-locking at your local auto parts store. That's less than the gallon of gas that is probably evaporating over a months time if you don't have it sealed on a hot day...

 

Also...check the vacuum line under (driver's side) fuel rail, for a disconnection or leak there.