[JimVR4]

Final plans for my seat heating retrofit

I had a chance to remove the glove box and inspect the fuse box over the weekend. I also unbolted the drivers side seat and had a look at the seat connector x275 and the seat module. After reading again Woodpecka's DIY for electric seats and the work the Placey reported in this thread I plan the following:

Driver's side
I'm coming from electric seats with memory so I already have the CAN bus control on pins 2,3 of x275. According to what I've read the driver's side heating is controlled by the CAN bus and I do not need to hook up the PWM wires to pins 1,5. My seat module has no pins in the heater connectors so I have to replace the module and of course I have to add the heating elements. After that the driver's side should work without coding.

Passenger Side
According to what I've read, the passenger side uses the PWM signals from the JBE to control the seat heating. Therefore I need to run wires from X11001 (pin10) to X279 (pin 5) and X14270 (pin 38) to X279 (pin 1). Also, these connections have to be extended into the seat module connector X013709 with X279 (pin 5) to X013709 (pin 4) and X279 (pin 1) to X013709 (pin 3) The power wiring on X279 (4) and ground wiring on X279 (8) are existing already for electric seats and fused with 30A at F45 so it should be sufficient power. I'll need to replace the seat module and add the heating elements. After that I need to code the car to get the JBE to work with the seat heating.

Parts List

E90 Heated seat retrofit for cars WITH SA 459 (Elec with memory)
64 11 6 966 406 A/C Control Panel 1
61 31 9 181 182 Replacement Button set, Center Console 1
61 35 9 196 936 Seat Module, Driver Side 1 $250.31
61 35 6 926 435 Seat Module, Passenger Side 1 $61.21
64 11 6 973 943 Heating Element, Seat 2 $179.84
64 11 7 140 539 Heating Element, Backrest 2 $139.40
64 11 7 138 803 Heating Element, Thigh 2 $34.92
61 13 1 383 776 Socket contact MQS, pack of 10 1 $7.95
61 13 1 392 234 Pin contact MQS, single 4 $3.96
61 12 6 908 725 Cable, Grey / Green 2 $3.36
61 12 6 902 614 Cable, Red / Yellow 2 $3.36
61 13 1 378 906 Double Leaf Spring, 0.5mm 2 $2.48
52 20 1 964 201 Clip, seat back 4 $3.96
CableTiesAndMore 1/8 inch wire loom 6ft $1.50

FYI: I had to sign a NCNR for the heating elements which have to be sourced from Germany. Also, the shipping charges were increased by $60 probably to cover the duties for the import.