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      12-12-2008, 05:40 AM   #1
First Lieutenant
Booster4075's Avatar

Drives: E90, 335i
Join Date: Mar 2008
Location: Northern California

iTrader: (1)

Lightbulb Heated Seat Retrofit

'Tis the season, and my wife's caboose could be warmer. Of course, I didn't get the car new, so I'm suffering with 40 degree temps (okay, not that cold compared to some of you) and I'm ready for my next retrofit project.

...and before you say it, NO - I don't want to add some aftermarket grids and switches. I want it to act like, perform like, and be otherwise transparent that the car did not come factory equipped with heated seats.

I've been doing a little homework. What I've learned (or think I've learned):

1) BMW does make a heated seat retrofit kit for the E90 for ECE cars only. This kit does not apply to cars with Sport seats (which I have) and does not include the appropriate switch panel that goes in the center console, which they tell you to order separately depending on other options installed (sunshade/front PDC/etc...)

2) In looking at ECE parts diagrams, all of the seat heater grids/elements are available separately. However, in looking at the US parts diagrams, elements are NOT listed (at all), leading me to believe that the elements may come as part of the leather covers or as part of the foam upholstery and are not available without them. This in turn would lead me to believe that all US replacement parts have the elements on them already - does this mean that all US cars are already equipped with the elements on them already?!?!

3) In looking at the switch panel, it appears that it plugs into the back of the heater & A/C control panel. I've been told that this retrofit still won't work unless the car is coded (Vehicle Order change - adding 494?) to reflect the add of heated seats.

4) It appears that there are different seat modules for vehicles with heated seats. This would be consistent with the ECE retrofit kit which replaces the seat modules (and they are different depending on whether or not the car has memory seats.)

Homework to be done:

a) Check the car - is it already equipped with the elements? This is 75% of the battle.

b) Confirm the vehicle order add thing - this makes it a little more complicated for the average owner since most dealers won't touch it.

c) Confirm that the rest of the wiring is there at the seat area. Since the modules are different, it would lead me to believe that the wiring is there.

Anyone interested?