Figured out - Lumbar support retrofit troubleshooting

krhodes1 · 07-29-2020, 08:31 PM

Figured this out - solution was in the coding forum. But it's not coding. If you don't have sport seats or seats with lumbar to start with, the car side of the seat harness is missing the pins for the power and ground to the pumps. The DIYs were from guys who had no-lumbar sport seats... Plug and play for them, I need to splice power and ground in the seat harness.

BMW, pinching pennies where they can...

I attempted the lumbar support retrofit into my e88 - and no joy, it isn't working. Per all the DIY's, this should be plug-and-play. Car is 6/10 build date, seat controller module is the same from 07-13 per RealOEM and others. Got the main wiring harness from a car with lumbar, plus the pads and pump, lumbar add-on harness, and switch. No particular difficulty installing everything, and every other function of the seat still works fine (power memory seats).

I have an e91 with lumbar, so I was able to confirm that the pump and switch are fine - in fact, I swapped them between cars. I have two of everything because I am going to do both seats in the e88, I actually ended up with *four* lumbar harnesses - tried all of them with no joy.

I actually just realized something - the DIYs were by folks with *manual* seats - maybe because I have power seats it does need to be coded since there is the seat module??

Any thoughts welcomed before I start yanking seats out of cars to swap parts around.

parameter416 · 08-01-2020, 07:53 AM

Good luck with it.

I've started scavenging all of the parts to retrofit them on my car (I have manual sport seats, with power side bolsters). Still need to find one more pump, and the wiring harnesses.

BMDoublYou · 08-01-2020, 11:41 AM

I did this successfully, went from heated manual seats, to heated manual sport seats with side bolsters. If you go from Manual to power/memory you need to connect to the can system of the car, if you are just looking for power to the lumbar, you need to piggy back 2 wires total per side, one for ground and one for power. All the info i found on the forums, inluding seat diagram pin outs, I believe you connect 8 and 13 (ground) and for me it was 4 and 7 ( power)

07-29-2020, 08:31 PM	#1
krhodes1 Colonel 1433 Rep 2,527 Posts Drives: 2011 328i Wagon Join Date: Feb 2011 Location: Westbrook, Maine, Port Charlotte, Florida iTrader: (1) Garage List 2011 128i [10.00] 2011 BMW 328i Touring [10.00]	Figured out - Lumbar support retrofit troubleshooting - coding?? Figured this out - solution was in the coding forum. But it's not coding. If you don't have sport seats or seats with lumbar to start with, the car side of the seat harness is missing the pins for the power and ground to the pumps. The DIYs were from guys who had no-lumbar sport seats... Plug and play for them, I need to splice power and ground in the seat harness. BMW, pinching pennies where they can... I attempted the lumbar support retrofit into my e88 - and no joy, it isn't working. Per all the DIY's, this should be plug-and-play. Car is 6/10 build date, seat controller module is the same from 07-13 per RealOEM and others. Got the main wiring harness from a car with lumbar, plus the pads and pump, lumbar add-on harness, and switch. No particular difficulty installing everything, and every other function of the seat still works fine (power memory seats). I have an e91 with lumbar, so I was able to confirm that the pump and switch are fine - in fact, I swapped them between cars. I have two of everything because I am going to do both seats in the e88, I actually ended up with four lumbar harnesses - tried all of them with no joy. I actually just realized something - the DIYs were by folks with manual seats - maybe because I have power seats it does need to be coded since there is the seat module?? Any thoughts welcomed before I start yanking seats out of cars to swap parts around. __________________ '11 328! Touring - Tasman on Chestnut, 6spd manual, factory upside-down "i" option '11 128i Convertible - Space Gray on Savannah Beige, 6spd manual, also '14 Mercedes-Benz E350 wagon, '95 Land Rover Discovery, '74 Triumph Spitfire Last edited by krhodes1; 07-29-2020 at 09:23 PM..
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08-01-2020, 07:53 AM	#2
parameter416 Private First Class 384 Rep 191 Posts Drives: 2012 128i M-Sport Coupe 6MT Join Date: Nov 2018 Location: Toronto iTrader: (0)	Good luck with it. I've started scavenging all of the parts to retrofit them on my car (I have manual sport seats, with power side bolsters). Still need to find one more pump, and the wiring harnesses.
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08-01-2020, 11:41 AM	#3
BMDoublYou Captain 117 Rep 622 Posts Drives: 09 E90 335xi / 08 E82 128i Join Date: Nov 2012 Location: True North iTrader: (1)	I did this successfully, went from heated manual seats, to heated manual sport seats with side bolsters. If you go from Manual to power/memory you need to connect to the can system of the car, if you are just looking for power to the lumbar, you need to piggy back 2 wires total per side, one for ground and one for power. All the info i found on the forums, inluding seat diagram pin outs, I believe you connect 8 and 13 (ground) and for me it was 4 and 7 ( power)
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