Official Fix to E39 LCM / LKM / Light Control Module

[S373N]

Morning everyone, my dad asked me to look into the headlights on his 2001 540i staying on - seems the light control module is definitely the culprit. I've done some searching and found a ton of different answers. I know the new module will need to be recoded to his car - but can a used lcm from another vehicle be used? I recently picked up an 03 530i module from the salvage yard and I'm hoping it's a direct swap (read that each lcm is slightly different based on the car's year, packages, etc.). One thread I found said it must be the dealer that recodes but another says and indy with a decent coding machine will work as well.

The part # I pulled was BMW 6 915 919 (086946057 104698 06 LEAR LCM-III_B 30441 which I could not find from on BMW's site). As I mentioned we currently don't have access to the vehicle to simply get the p/n.

Thanks!

[cnsorial]

Yep, it should work. Just recode using NCS. Various threads on it.


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[S373N]

Thanks, cnsorial. I'll ship this module back to my dad.

Does anyone know how long you can go on a swapped LCM without coding before getting the tamper dot? I'm planning to have the car shipped down to me in Texas but as-is the battery will die on the trailer due to the headlights staying on. The car is not registered so we can't drive it to an indy and my dad isn't 100% comfortable with coding himself.

[geargrinder]

You'll need to change the vin and mileage in the donor cluster with PASoft or another tool that can do raw writes to fix the VIN and either correct the mileage or clear the mileage. So not just an NCS recode. You're saying the headlights stay on even w car off? Just headlights or tails too? For a transport situation like that I'd prob just unplug the problematic bulbs until you get the new module coded up correctly, and warn the truck driver the lights don't work.

- - - Updated - - -

(in other words don't bother sending your dad the module, just sort it out yerself when the car arrives)

[billh]

Easier method is to disconnect the battery once the car is on the trailer/truck. No battery drain!

[geargrinder]

No.

Transporters need to move the cars, often more than once to juggle cars on and off... that makes for a real ballache for the driver. If its your trailer/truck, fine works great, but for a transporter, no. Unplug the malfunctioning lights for the guy, let him know, done.

[S373N]

As I expected, my dad is having trouble installing BMW Scanner / PASoft.

Can anyone confirm if the tamper dot will permanently appear if he only swaps the LCM? I guess the plan would is to only swap the LCM (so the headlights turn off), ship the car down to Texas, and then I'll handle the coding about a week after the swap.

Edit: geargrinder: my dad does not want to ship it as-is / with the lights disconnected as he's concerned the battery will still drain.