We're getting ready for a short trip (1200mi) up to the frozen tundra of Georgia for a few days. Temps will get to a bone chilling 39F at night according to the forecast. I thought I would check all the heating stuff in the car since we rarely get to use it.

I noticed that when I push the driver's side heated seat button the light did not come on nor did the seat heat up. So I tried the passenger side and the button lights up as expected ...but...the driver's seat heats up instead of the passenger seat.

I checked all the connections in console and under seats and all seem fine.

Any suggestions on where to look next?

 

Well that confirms the Wife is driving! Did you swap the plug in wiring to the other seat switch?

 

Hopefully I can get this sorted before we leave on 4/5.

Everything looks correct. I even pulled the console to check the connection on the switch pack.

Can the seats be swapped to opposite sides for testing?

 

Lol on the frozen tundra in Georgia. I used to live there and it was a bit too warm for my tastes.

Did you try to swap the seat modules from one side to another to see if one was acting up? It shouldn't make the other seat turn on regardless, but at least you could rule it out the driver's seat module being bad. It'd be interesting to see if any of the problems follow the module.

 

I've seen debris get in there and foul up the switch operation. Fiddling around with the switch cures it, but I'm sure you've been there done that if you've gone so far as you have. Is the switch travel normal?

 

Yeah the switch seems normal. The weirdness of the passenger button turning on the opposite seat is what has stumped me.

 

Try a hard reset? Once my sport swtich started controling something else (I forget what).

 

Yeah a reset sounds like a good idea. I'll give that a shot tomorrow.

 

Are you POSITIVE this is what happens? In my car, these seat heaters are sort of slow to start up. It probably takes several minutes before real heat is felt. A quick test involving both seats would probably confuse things. You might want to test just one seat at a time, and separate each test by several hours. Also, when the seat heater is turned on, there should be a faint relay noise coming from the module under the respective seat. Maybe this can help link button to module. Just a thought.

As suggested above, you might want to swap the seat modules (under the front edge of each seat) to see if other clues are revealed. Heaters not working are common symptoms of module problems, which are themselves very common.

I was trying to think through what would have to happen to swap these buttons. Either the harnesses to the modules would have to be swapped, or the console would have to be "different". Unless the carpet was pulled out and the harness re-located, the harness theory is highly unlikely. For the console, could it possibly be a British part? Although the net result should be the same, (right button heats the right seat, etc.), it is possible a British part could possibly swap these seats. I would take pictures and double check any part#.

Best of luck, keep us posted.

 

Don't forget the heater is tied to your selected temperature. Given that they will heat faster if you set it for say 88 degrees.

Just tried it tonight, getting warmer in NJ, had the temp at 74 degrees. Wondered what if? And punched it up to 84 degrees. There was a noticeable temp change in a short time.

 

From the wiring diagram (2003 - should be the same or similar), the center console switch pack containing the switches connects to the Body Control Processor which interprets the switch states and sends out the appropriate SCP messages (different for driver and passenger) on the SCP data bus to the two seat control modules -as well as lots of other modules. The electrical signals at the switch pack for driver and passenger seat heater switches and LEDs are on different pins of the same connector, so it is unlikely that these signals got swapped accidentally unless someone messed with the wires and pins. More likely there is short or other malfunction inside the switch pack. Alternatively, the BCP is sending the wrong messages, or the seat modules are interpreting the messages wrongly. I'd tend to look at the switch pack first.

 

I noticed that someone else posted this exact same problem with the seat heating and I had forgotten to update this thread with my resolution.

In my case the problem was most likely related to a poor connection under one of the seats. Not sure which one because I removed both of them while I repaired the rear driver side window regulator.

It was some time after I put the seats back in that I noticed the issue had resolved and both seat heat buttons were back to working normally and seats both heated as expected.

Glad its fixed as the temps have dropped to a bone chilling 60 degrees at night.