2004 Gmc Yukon xl

What you did wrong was to assume that those codes meant the sensors are causing the problem. That's not necessarily the problem. The codes merely indicate a situation that the PCM has detected. Now you have to figure out what the cause was. It's not as simple as read a code and change a part as so many people believe.

I kinda figured that. I had my Denali since it was new and I had it serviced at the dealer up until recently. I'm no tech, but I'm pretty good with my hands. I just need some guidance. Is there anything else you need to know to help me?

Check all your fuses and look the harness over carefully for any breaks or burns. Those are 2 different codes both referring to the same sensor so the wiring would be highly suspect. You have both a heater code and a signal code. They are separate circuits and that has to be more than a coincidence.

Wow. I will give it a looksee tomorrow, and let you know. while I have your attention. My driver's side window only works when the ignition key's in the accessary position. I hooked up a snap on flash computer to run a test, and it didn't tell me anything. do you think it's the module in the door or the door switch?

That's a subject for a new question. We can't address multiple problems or multiple vehicles in the same thread. It gets way too hard to follow, especially if another expert gets involved.

Ok. I wil post another question about the window issue. Thanks for your advice on the 02 sensor.