Heated seat not working

[alvocado]

My heated driver's seat stopped working suddenly last winter and I'm looking for help on troubleshooting steps. The switch light still comes on so there is power to it (I assume). The heat stopped working rather suddenly and does not function on either high or low.

 

Should I start with checking the power output at the switch with a voltmeter or is there another electrical component under the seat that might be the culprit? I don't suspect any exposure to water or moisture so this must be a component failure.

[Yukon04]

What vehicle/year/etc?

 

The switch in the door has little to do with the heated seat actuation. The switch is hardwired to the door module and the door module sends a communication signal via class II protocol to the driver's seat module (MSM). The MSM receives the signal and turns on the appropriate setting via hardwiring.

 

First check any fuses pertaining the heated seat system. I believe that the heated seat system has it's own fuse. Check it. I assume the rest of your seat works so the connection from the seat harness to the body harness is probably OK, but check it anyway. Verify that the connection is fully seated and locked. Without a CAT (Can-bus Analyzer Tool), there is no way to verify that the door module is sending the correct (or if at all) signal to the MSM. Is it only your driver seat that doesn't work? Check this as well. Check all connections under the seat. Heater pads have small 4-way connectors near the suspension springs. Check them.

 

Did any of this fix it? If not, let me know...PM me.

[alvocado]

What vehicle/year/etc?

 

The switch in the door has little to do with the heated seat actuation.  The switch is hardwired to the door module and the door module sends a communication signal via class II protocol to the driver's seat module (MSM).  The MSM receives the signal and turns on the appropriate setting via hardwiring.

 

First check any fuses pertaining the heated seat system.  I believe that the heated seat system has it's own fuse.  Check it.  I assume the rest of your seat works so the connection from the seat harness to the body harness is probably OK, but check it anyway.  Verify that the connection is fully seated and locked.  Without a CAT (Can-bus Analyzer Tool), there is no way to verify that the door module is sending the correct (or if at all) signal to the MSM.  Is it only your driver seat that doesn't work?  Check this as well.  Check all connections under the seat.  Heater pads have small 4-way connectors near the suspension springs.  Check them. 

 

Did any of this fix it?  If not, let me know...PM me.

 

<{POST_SNAPBACK}>

 

 

 

It's a 2002 Yukon Denali. The passenger heat works fine and all of the power controls are functioning on the drivers seat. I'll check connections and the fuse tonight. Do you know which fuse location controls the heated seat or is it labeled on the fuse panel? If it's a single fuse for both seats, it's probably something else since I do have heat on the passenger side.

[GM-Tech]

I believe Yukon04 is somehow involved in the building/designing of the seats, so he would be more of an expert than me, but from experience, the most common failure we see is an open heater wire in the seat heater pad. There's a lot of flex there over time from your butt on sittin' on it.

 

Since the back and seat cushion heaters are wired in series, if one element goes, neither will work.