We got a code of PO455 and were told it was the gas cap. $53 later, and the engine light comes back on with the same code. GM. says that we needed to replace the purge valve because the code reader was also saying no flow. So I tackled that today. I took pics along the way in case anyone else has to do this. Our H3 has also been idling high and that was another way GM came to the conclusion that it was the purge valve being plugged up.

At the GM dealer that diagnosed the problem the purge valve from them was $50. We called another GM dealer across town and theirs was $44, so we went with that one. Exact same one from both places, just a little cheaper at the one place.

The Hummer is running great now. Light hasn't come back on, so keeping our fingers crossed. It's also idling normal too, so I am sure this has fixed the problem.

I am posting this because the GM dealer would not tell me the easiest way to get to the purge valve to replace it. I bought the part there. They told me I was welcome to make an appointment and have it done but that I couldn't speak to a technician. I was pissed. Would have taken 5 minutes to tell me. Somehow I found it on the internet. Didn't tell me how to do it. Just said to get to it through the wheel well and not from under the hood.

Here's how to do it.

Tools needed:
Flat screw driver, to remove plastic clips that hold on inner fender liner.
19mm socket to remove lug nuts.
10mm socket to remove mud flap, disconnect battery, and the bolt that holds purge valve on.

Disconnect the battery.

Remove the driver's side front wheel and tire.
(Jack it up, of course and place a jack stands as a secondary supports)



Then remove the inner fender liner.(The big black plastic shell under the wheel well) Also remove the mud flap.


Here's a couple images of the purge valve in place. It is up against the engine block attached with one bolt size 10mm socket.



Remove the bolt. unplug the electrical connection. In the pic it is the wire with the red plug on the end. Remove the two air hoses that are held on by plastic clips.

When you get the old purge valve out there is a metal bracket attached to it that you will need to slide off and put on the new purge valve. The bracket is what attaches it to the motor block.


Off of old one and on to the new purge valve.


New one installed. Electrical wire and air hoses hooked up and 10mm bolt put back in.




Then put the inner plastic back in and the mud flap then the tire, and that's all. I hope this helps if anyone runs into this problem.

 

Nice job. THANKS!!!!

 

Thank you, hopefully this can help someone else. I am really sick of the dealerships not being helpful whatsoever. I understand that they want to make money, but like with this. I bought the part at the dealership. They made money on that part, but were unwilling to talk to me for a couple minutes about the best way at getting at the purge valve. Both dealerships I talked to said I would have to make an appointment at $90 per hour. I know there are some things that I cannot do on my own and have to take it to the dealership to have done which I always do, but I feel they should be helpful to us in a situation like this where I can do the project with just a little advice.

I'd like to encourage everyone that does repairs to their H3's to photo document it if they can like I did here to help everyone out so we can do minor repairs like this on our own if we want to try it.

Thanks again doc.

 

Thanks for that information and all the pictures.

This could be my next repair if my check engine light comes back on after replacing my gas cap, filling the tank of gas and erasing the P-0455 code.

Will save me and others a lot of money for a simple simple job.

 

Hi, Thanks for the instructions! I had a question that maybe you could help me with. I took my H3 to a garage with a P0443 error code. They replaced my vent valve and fuel pump but error code is still on. Could this be a purge valve problem or a problem with my PCM? My battery dies every couple of days even though its new.....
Any help would be appreciated!!!

 

This question doe NOT need to be in this 2 year old thread!

https://www.hummerforums.com/forum/n...bumping-23220/

 

I somehow missed this the first time around, glad I got to see it.

 

thanks for the pics and the write up, I'll be tackling my purge valve in a few days when it comes in, going to have this thread saved