Seat heater

[[__--MUD--__]]

[[__--MUD--__]]

Just yank that above plug under the seat. The door module is what powers it.

There is a tsb on the heating elements not working all the time when turned on, but I see nothing about them being on by themselfs.

There is updated firmware for the door control module for 2003-2005 that corrects the issue in that tsb. Might try getting a dealership to reprogram that module. All the diagnostics requires a tech2.

[[__--MUD--__]]

****, you have an 06. guess you already have the newer firmware.

[[__--MUD--__]]

Just sitting here thinking... this poped out at me-

The heated Seat switches are momentary contact switches and are inputs to the driver and passenger door modules.

does the physical button face seem loose? Like the spring broke behind it. If the spring broke and its not holding that button open...as you drive around it could be rattling around closing the contact- activating the system.

Here is the input to the drive door module-

[[__--MUD--__]]

Pin #3 & #9 are the actual on/off signals.

In theory, if those were disconnected- you have removed the physical input activators and kept the function indicators operational- Switch is disabled, but you can still see if they are on/off.

Door module communicates to the seat module throught the data bus. Like that heated seat option activated through the bypass module for the remote start...I "think" it contacts the seat module directly through the bus. Dont believe it sends any signal to the door module.

Here's the seat modules-

[HUMTECH]

Good call, never thought of that myself

Originally Posted by [__--MUD--__]

Just sitting here thinking... this poped out at me-

The heated Seat switches are momentary contact switches and are inputs to the driver and passenger door modules.

does the physical button face seem loose? Like the spring broke behind it. If the spring broke and its not holding that button open...as you drive around it could be rattling around closing the contact- activating the system.

Here is the input to the drive door module-

[pdxrealtor]

Right on MUD- all that info is much appreciated!

Now I have to make some sense out of all of it.

RE: the TSB.... In all my Google searching and result reading I did come across the going off automatically after being turned on. Those problems seem to have been narrowed down to the MCM under the seat, and the actual element itself shorting out.

The only problem solver I've been able to find for the on / off ghost is the door module, which is connected to the bottom of the window switches in an 03 Yukon. http://www.fixya.com/cars/t1790846-0...lution-heading


A side from that it's a bunch of 'what I do I do' without a bunch of 'this is what you do' when it comes to auto on/off issues.

I really want to avoid the dealer. I think an acquaintance has a body code reader, but it's not a tech 2. That should work, no?

OH- and RE: the actual switch on the door. That little SOB, when turning on a seat heater at will, will really test a man's anger management issues. I was ready to rip the wires right off that damn circuit board and the only reason I didn't is because I was afraid the heater would still come on leaving me really ****ed.

Anyways, it is removed from the door at this time. I too thought it could be a switch problem because when things go haywire the input of the seat heater BACK button doesn't always register, or is delayed. Once you remove the plastic cosmetic buttons you'll find little low profile rubber buttons attached to the circuit board. I don't think there's a spring behind that. I think it is just the rubber molded the way it is that causes the button to auto return from depress. From what I can see there is nothing wrong visually with the circuit board the switches are attached to.

[[__--MUD--__]]

yea, I call'em rubber nipples

I havn't torn into one of those buttons yet, so I had no clue besides there being some type of mechanical tension...spring, nipple what ever...

If there is some type of short or issue in the memory seat module that is activating the heated seats- I would disconnect the drive door module. Obviously you will not have a visual indicator- if the heating element is on...but you should feel it, and it will also tell you that the door module is NOT what is activating the heated seats.

You will have a completely dead door during testing, but w/ no tech2- I think you can live w/ it for a bit.