Rear heated seats

[Bmwe5320023.0]

Thanks guys, I've been staring at this chart for a while but not knowing how to read the diagrams fully I can't quite figure it out.

I'm not sure about these symbols



One of them might be a thermostat responsible for turning off the heat when it gets too hot?

My goal is to make the seats activate when the car is started with a remote.

So I understand the switch has 5 pins.

Pin 1 heats the backrest
Pin 2 heats the back seat
Both activate when key is in 2nd position
Pin 3 is ground
Pin 5 is another power from the relay

Do pins 1 and 2 get their power from K93 relay as well?

Pin 4 goes to the light control module Pin 1, which is
1 A Signal line, night lights Connector terminal 58

Am I correct to assume that the light module simply lights up the botton?

My best guess how this works is that pins 1 and 2 get power from pin 5, when the button is pressed, and if the key is in position 2.

Please correct me if I'm wrong about any of the above.

[Clavurion]

Terminal 58G from LCM is instrumentation lighting = only button back light.

Terminal 15 = ignition switch pos. 2 activated voltage supply. Comes to pin 5 via unloader relay.

Pin 2 is NTC resistor = temp sensor

Pin 3 is ground (Terminal 31).

The button has semiconductor FET:s to give supply voltage to heater pads. Depending on switch position the supply is cut when set temp is reached.

[Bmwe5320023.0]

In this case if I connect an ignition wire from the remote to pin 1, it should activate the heated pads?

[Clavurion]

Originally Posted by Bmwe5320023.0

In this case if I connect an ignition wire from the remote to pin 1, it should activate the heated pads?

Yes, but the elements would be on full power (without temp regulation) until you turn them off.

[Bmwe5320023.0]

I think that should be fine since the remote would be on for about 30 min

[Bmwe5320023.0]

Just confirming that this seems to work.
I haven't been able to run the car for too long, it's still in my garage and I can't take it out yet.

But when I remote start, wire #5 gets 12 volts and the seats start warming up. Actually I get 11.75 volts on wire #5. If however I press the button for the heated seat, voltage on wire 5 jumps to 12.5.
Now I need to do the same for front seats, and maybe steering wheel and rear defrosted if possible.

[80stech]

I'm not a big fan of remote starters but I would think that a modern one would have some outputs to activate heated stuff and A/C ??

[Bmwe5320023.0]

It has tons of outputs on the remote starter but the question is where to connect it to activate the button
There's many outputs for 500 mA positive and negative etc.

[80stech]

Haha, yes now I see what you mean! The button is in the controller module so you would probably need to take it apart to gain access. You might be able to get away with bypassing to full power with the seats and steering wheel but I wouldn't try it with the rear defroster.

[Bmwe5320023.0]

Disassembly was rather simple


I take it you meant soldering something on the board to activate the heated function instead of providing direct voltage to pin 1?
This seems too advanced lol!