Top 10 2003 GMC Yukon XL Questions & Answers

If you forced the pads back into the calipers without loosening the bleeders you probably forced gunk into the abs modulator valves. Sometimes doing the automated bleed proceedure (need Tech or Bi Directional Scanner) will bring things back to life.

I fixed mine by using fine steel wool to clean the brass contacts located at the right upper door frame on the right door as viewed from the rear of the vechicle.

This is a follow up to the problem I posted. (Like many others out there). Guess what.... there is NO RECALL on the Memory Control Module Computer for the seat heater controls. Sorry, no freebies on this one. There is a TSB (Technical Service Bulletin) from GM that advises the repair shop (dealer) to investigate and install a new MCM (Mem Control Mod. So, sorry, there's no fix except to replace.....at your cost. But, I have good news! The GMC dealer only wants to charge us $495.00 for a new MCM! Isn't that great news! Uh.....no, it's not. I did, however, find that Ebay carries a stock of them (and a particular vendor that only stocks GM products). Ebay inputs them as "door switches", so be sure to look for your year and model with "door switch" as your search term. The vendor that supplies them on Ebay, and at their store front, is called "G and R Auto Parts" from Oklahoma City, OK. They only deal with GM used parts, and I found mine for $50! What a deal! I just installed mine and it works great! I called down to talk with them and they are great to deal with. Read on if you want to see the technical side of the repair.....

I consider myself a "weekend warrior" with computers and light mechanic work on cars, so I did my own diagnostics on the car to find the specific issue that caused the seat heaters to freak out. There are 2 computers that control the seats. One is located under the drivers seat in a black box about the size of a 5x7 picture frame (1 inch thick). The other computer is located under the window switches on the drivers door. Actually, the switches and computer are all one unit. The computer boards in this "switch box" control multiple things that I'm not entirely sure about. I do know this..... The green plug goes to the switch box for the seat memory/seat heater/ pedal memory. That's as far as we needed to go. With the standard varation control that we all learned in chemistry class to add/subtract one variable at a time, we deduced a couple of things. 1, the computer circuit board was reaching in excess of 330F degrees! We got the temp reading from an infrared thermometer for $15 at Radio Shack.(Good purchase!) I don't know much, but that can't be right. After we played around with that for a minute, we were able to tell that a certain computer chip was getting too much juice and it created jumps and skips in the controls that made the seat heater come on and off. It also got so hot that it initiated the windows and mirrors to do crazy things. Wild stuff! Then, we looked closer at the circuit boards..... there were a few burn marks by some resistors that just happened to be hooked up to the Green plug. Ahhhhh, the plot thickens. After that, we investigated a few more areas on the board and found that there was also a little corrosion around the green plug. Bingo! We theorized this..... Because the com chip got so hot (We don't know why, it's only got 81,xxx miles), the chip send a power surge to the green plug resistors. It burned out the resistors, thereby creating a dam for the power to go nowhere except burn the chip faster.(330F+) This initiates a powersurge in other areas and created the voodoo ghost effect of the seat heaters going on and off (And later the windows and mirrors). Because the chip burned the resistors, it burned off the protective coating that is applied to keep moisture out of the circuits and solder. This created the corrosion and possibly even more problems, but hey, it only took one time to see the effect. Crazy huh?!?!?!

There it is..... My theory and my fix. Hope this helps. As always, please contact me anytime if you have any problems.

Thanks and good luck.

Brandon
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you don have to do much to that gmc as long the coil is good, just replace all 8 spark plugs, air filter and basic oil and filter change; use good brands of oil, such as castro, mobile, shells ect. if your the original owner and have high miles and never have replace thermostat, I would go ahead and have it done, I would not wait until it fail and over heat on you. if you have done lot of pulling with your vehicle and have 75-100k mile, have your transmission flush with new filter, it will give the tanny life last a bit longer.

Behind the center console to the left behind the glove box with two screws holding a cover on it. Will have to remove glove box and a posiable air duct and bracket etc.

If this is an intermittent problem,
remove the IPC 10A fuse in the fuse box under the hood,
not in the fuse panel by the driver side door,
for 5 minutes.
The electronics will reset.

This is usually due to an airbag deployment. It's the code for the front left circuit (driver's side). Most likely, the driver's side airbag deployed and the bag and module were replaced, but the module circuit ring in the column wasn't replaced. When the module senses the need to deploy, it sends a signal to the ring opening the line for the current to flow and causes the bag to deploy. Problem is, the circuit stays open, and casues a fault code. The unfortunate part is, until the curcuit is replaced, the SRS system in inoperable and will not deploy again in the event of an accident. You'll have to have the steering wheel pulled to service this item and should be done by a certified technician. It can be expensive, but worth the price of your safety.

Try this remove the ckt breaker for the power seats the ckt breaker is located in the fuse box inside down by the drivers left foot. leave breaker out for about 10 seconds then reinstall it and see if the seat starts moving. If it does there is a reprogram for this and needs to be done by a dealer or someone who has access to be able to reprogram your vech.
several things could cause your heated seats to not work. If the seat and heated seat seat stopped at the same time could be the reprogram could fix it. If the heated seat quit working at a differant time it could be the seat heater element. get a schematic of the heated seat and ohm the wires for the element. If either element tests open then the element will need to be replaced. You might as well replace both of them at the same time since the seat covers have to come off to replace the seat heaters.(back and bottom ) If one element is bad then both heaters quit working.

Need more information but here is where all your O2 sensors are located
Bank 1 Sensor 1 - Driver's side, before catalytic converter Bank 1 Sensor 2 - Driver's side, after catalytic converter
Bank 2 Sensor 1 - Passenger side, before catalytic converter
Bank 2 Sensor 2 - Passenger side, after catalytic converter
Thank you for using fixya and good luck

I HAVE THIS EXACT PROBLEM. If you got this repaired, what was the fix??