I've searched the forums and can't find the exact answer. I have a 2004 Tahoe Z71. Both front seat heatersstarted shutting off after 30 seconds at the same time. They will come on, heat, then shut off after 30 seconds. The seat and back elements both get hot if you turn it on every 30 seconds. All other electronics in the seats work fine as far as I can tell.

The dealer first said the computer fault code was a bad bottom seat element - in both seats that went bad at the same time. I told him the seat bottomsheat fine. They called back and said it was the seat back elements that werebad. Again, I told them that they will heat up if you keep pushing the button.

They continued to stick with the diagnosis that the seat back elements were bad and the fix was to replace both seats. They recommended to replace the backs and bottoms. No thanks - since the seats will heat up just fine if you turn them on in 30 second intervals.

What is going on? Any ideasor help?

 

It is probably not a faulty heat element.
This problem occurs if there is a fault in the common 5V reference signal.
The problem is most often an internal short in the adjustable accelerator pedal sensor, the seat recline position sensor or the heated seat thermistor signal circuit.
You can unplug the accelerator pedal position sensor and check if the seats heaters work properly, if they do then replace this sensor.

Have your dealer reference GM Document ID # 1864985 for further information on the proper diagnoses and repair of this problem.

 

Thanks for the help ZX1100F1. Is it difficult to unplug the accelerator pedal position sensor? Can I reach it down around the pedals?

 

Piece of cake to disconnect:
Standing on your head you will see a black and gray plastic wire connector (with several wires going into it) on the accelerator pedal just above your foot pedal, unplug it and test the seat heaters.

 

OK, I stood on my head, but couldn't find the plug. I started disconnecting several plugs but I don't think I actually found the right one. I never unpluged a connection that disabled the pedal adjustment motor.

I did however unplug smething that caused my engine to run terrible and set an engine fault code that took 3 days to clear off.

Any more specific instructions for diagnosing the cause of the seat heater problem for a technically inclined but novice mechanic?

 

Did anyone in this thread ever figure out what the problem was I tried the trouble shooting tips here and have posted a thread that got alomost no response, but my Tahoes driver side heated seat will shut off after 30 seconds, and the passenger side works as long as the driver side is not on. if the driver side is on they both shut off. Someone here has got to know what the answer is.