So ever since i got my qx50, the heated seat was super wonky. if i turn it on, it would warm up nicely, but not stop and it would get burning hot, like unbearable as if the seat was on fire. It has 5 heat settings and even the lowest made no difference, after about 15 mins of burning hot seat, it would then eventually it would shut off and get cool and not respond to the knob. Last year the wife was driving and i was passenger and I tried the passenger seat and noticed it’s completely pleasant, the temperature dial works as it should.
I just ran out of bumper to bumper last year and i figured even if i took it in they would say 'Hey it works!' So i tried taking it apart last year and tried to follow the diagnosis from the service manual but i couldn’t pinpoint what’s wrong based off the manual’s suggestions. I also followed the wiring diagram but Nissan does a poor job of documenting wires. Most of the colors on wires and pin positions on the controller shown in the FSM are wrong.
I figured it out tonight, they friggen wired two of the 6 pins going from the switch to the control unit backward! There is a pin that goes high to 12v to tell the control unit the switch is on, and a second pin that is wired to the potentiometer in the knob on the console that steps up and down the voltage to tell the controller how hot to make it. It was wired backward from the factory! It was getting a full 12v on the potentiometer pin and switched voltage on the turn on pin, so it would just run burning hot and shut off.
I confirmed this by comparing to the passenger side, which didnt have this problem and worked fine and confirmed it was correct there.
I tried de-pinning and replacing the pins on the controller but it was too difficult so I pulled the center console and swapped the pins on the connector for the switch and boom which was a much easier connetor to de-pin, it FREAKIN WORKS!!!
If anyone needs to do this, you need to swap the blue and grey wires on the driver's side connector for the control knob. Only down side is getting to it requires taking out the center console, but that's easy to do, about a half hour job if you take your time.
Anyone else have this problem???