[krhodes1]

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've read the DIYs, and had no particular trouble installing the parts. Replaced the main seat wiring harness with one from a car with lumbar, ran the lumbar harness, installed the pad, drilled the hole for the switch and installed it, and installed the pads and pump. And no joy. All the other power seat functions work fine, but no lumbar action, pump doesn't run. I bought two sets of everything so I can do both seats, so I swapped out the easy bits, the switch and the pump, still nothing.

So before I take the seat out of the car to do more testing - this is strictly plug and play, no coding needed, right? And no separate fuse for the lumbar system? I didn't see anything about coding in any of the DIYs. So it's probably a broken wire in the lumbar add-on harness or something since everything else still works from butt heat to memory otherwise. I actually ended up with four of the lumbar harnesses, as the main harnesses I bought came with them and so did the lumbar pad/pump assemblies. But of course, you can't get at the connector with the seat bolted down. Hindsight being 20:20, should have tested it before I put it all together.

I will also say, the hardest part of this is getting the darned seat trim off! It totally feels like it will break before it comes off the first time.

This is actually for my e88 128i convertible (my wagon has the premium package), but the seats are the same as e9x seats and this forum gets WAY more traffic than the 1-series forum.

Curses to the evil wanker at BMW who decided to make the lumbar support part of the premium package and not part of the stand-alone electric seat option!