Electrical LCM issue, my own stupid fault 🤬

[oldgitdave]

OK, this is extremely embarrassing & I've called myself a few choice things I can tell you! I'll try to keep it short but I definitely need help please. Basically the light switch doesn't work & neither do the indicators (could be more!)

I've fitted a mfsw that I've just bought & had recovered by the guys at Royals. In doing so I used this great 'how to': https://z4-forum.com/forum/viewtopic.php?f=26&t=16422&hilit=mfsw but I still managed to screw it up :headbang: ! I had to fit the retrofit cable & I somehow managed to splice the red/white/yellow wire into wire no. 22 instead of wire no. 21 of the LCM (light control module). So, on reconnecting the battery the mfsw didn't work & neither did the lights or indicators . I disconnected the battery again & eventually found my stupid mistake which I have now rectified. The mfsw works fine now but I still have no lights or indicators! I've checked all relevant fuses i.e. 14, 23, 59 & 60 & all are fine. Have I fried the LCM or maybe it needs to be recoded to the car? I really don't know what to next. Any assistance or advice would be welcomed. I've disconnected the battery again for now. To say I'm pi$$ed off at the moment is an understatement :x .

 

[mr.tourette]

ph001 is your man here.. hopefully he will pick up on this

 

[oldgitdave]

ph001 is your man here.. hopefully he will pick up on this

Thanks buddy

 

[kis]

Wheel looks good

Have you tried to run diagnostics? If anything pops up, it could be as simple as resetting any faults?

 

[oldgitdave]

Wheel looks good

Have you tried to run diagnostics? If anything pops up, it could be as simple as resetting any faults?

Thanks

I forgotten I had an OBD scanner so didn't think about that so thanks. Just tried the diagnostics & this is what pops up:

Car Scanner ELM OBD2
DTC report
Selected brand: BMW

============1==============
FF00
Raw code: FF00
ECU: 12
============2==============
299A
Raw code: 299A
ECU: 12
Status: Test is inhibited by other DTC
============3==============
P0701
Raw code: 0701
ECU: 12
Status: Confirmed
OBDII: Transmission control system - range/performance problem
BMW: Transmission Control System Range/Performance

No idea what any of that means but I don't have any auto box issues as far as i know. Unless my mistake has caused something? I cleared the codes but still no lights etc. Brake lights don't work either .

 

[oldgitdave]

Little update, I've been in touch with a local BMW indy who has great reviews around here and surprisingly has replied to me twice today . Here's a slightly edited version of his response:

"When the modules enter emergency mode they will put all the lights on as failsafe. Given the vehicle hasn’t done that suggests a failed computer.

Yes we can program the LCM, but it will unlikely resolve your issue. I’d recommend supply another unit and book it in so we can take a look at it and fit and code the other unit. We will need to adjust the vehicle order for future repair work so the modification is recorded within the core electronics."

I then discussed the fault codes I'd read with him & got this:

"As far as I can remember the data line required for the LCM to communicate from the OBD socket need the data to pass the the Kombi. The Kombi is the gateway that changes the Dx to I bus, which is also K bus. Which is how they all talk together. The LCM is the back up computer for the Kombi and stores all the mileage data and VIN and FA details. An error with wiring will render it speechless as such.

It’s not uncommon to find transmission errors. But with a BMW the technician must only adhere to the complaint as there are many many faults reported and it’s decision to include them or not. So if you’ve not noticed anything then it’s unlikely there is anything wrong. So don’t worry about the transmission."

I'm way out of my comfort zone with Dx, I bus & K bus etc. but thought one of you guys out there might like to comment.

I don't suppose anyone has a suitable LCM light switch for a 2004 Roadster in their garage they don't want ?

 

[markplant]

Can I ask indy you used, just for ref

 

[ronk]

This all sounds scary!

 

[ph001]

Hi there, apologies...just spotted the thread. Sounds like your indy is trying to scare you with jargon to put you off the job and justifying costly repair charges. At best it’s a load of irrelevant nonsense.

There is a fair chance you have damaged the LCM module, so get a used one from somewhere like quarry motors and simply have an indy code it to the car (I’d suggest a different one to the above). Should be no drama really.

 

[oldgitdave]

Hi there, apologies...just spotted the thread. Sounds like your indy is trying to scare you with jargon to put you off the job and justifying costly repair charges. At best it’s a load of irrelevant nonsense.

There is a fair chance you have damaged the LCM module, so get a used one from somewhere like quarry motors and simply have an indy code it to the car (I’d suggest a different one to the above). Should be no drama really.

Thanks so much for that . I'll take a look a quarry motors too. There's a small but good garage just round the corner from me. I'll go talk to them & see what they can do. Is it best for them to fit it & then code it or could I fit it & then drive it round to them to do the coding only?

 

[ph001]

You can certainly try fitting it on your drive to make sure it restores your indicator function etc first. You will get a mileage tamper light on the dash though as mileage won't tie up so then you will need diagnostics to reset that but at least you can drive safely. If it's just around the corner though I would be tempted to let them fit it. 5 minute job plus 10 minutes coding max.

I am almost certain Quarry motors will be able to sort you out with an LCM module. There is not much demand for them as generally very reliable.

 

[oldgitdave]

Sounds like a plan. I shall report back when it's sorted. Thanks again for help .

 

[oldgitdave]

You can certainly try fitting it on your drive to make sure it restores your indicator function etc first. You will get a mileage tamper light on the dash though as mileage won't tie up so then you will need diagnostics to reset that but at least you can drive safely. If it's just around the corner though I would be tempted to let them fit it. 5 minute job plus 10 minutes coding max.

I am almost certain Quarry motors will be able to sort you out with an LCM module. There is not much demand for them as generally very reliable.

OK, I've managed to source a replacement LCM & have fitted it after a chat with my local indy round the corner. And yay it works , all lights back to normal.
I have the tamper light on as expected but also the airbag light :? . Maybe there's a tie in with the 'new' LCM as it wasn't on with the old one & I had the battery disconnected the whole time. Anyway no biggy hopefully, she's going in tomorrow morning to have everything reset & coded .

 

[ronk]

Sounds like it’s going in the right direction

 

[oldgitdave]

Sounds like it’s going in the right direction

Thanks Ron, I feel a lot happier now. I was thinking it was going to be very scary for my wallet but so far not too bad (though Mrs OG has been giving me some stick, rightfully so I suppose ). Hopefully back to normal by tomorrow evening :roll:.

 

[ph001]

Good man

 

[thecremeegg]

You can certainly try fitting it on your drive to make sure it restores your indicator function etc first. You will get a mileage tamper light on the dash though as mileage won't tie up so then you will need diagnostics to reset that but at least you can drive safely. If it's just around the corner though I would be tempted to let them fit it. 5 minute job plus 10 minutes coding max.

I am almost certain Quarry motors will be able to sort you out with an LCM module. There is not much demand for them as generally very reliable.

OK, I've managed to source a replacement LCM & have fitted it after a chat with my local indy round the corner. And yay it works , all lights back to normal.
I have the tamper light on as expected but also the airbag light :? . Maybe there's a tie in with the 'new' LCM as it wasn't on with the old one & I had the battery disconnected the whole time. Anyway no biggy hopefully, she's going in tomorrow morning to have everything reset & coded .

The LCM needs to be a lower mileage than the car is on as they have to match the two together - the LCM holds the mileage for the car, hence the tamper light. You can add miles but not take them away. Hopefully it's just something that can be reset.

 

[ronk]

Will the tamper light go off when the cars miles catch up to that of the module?

 

[oldgitdave]

You can certainly try fitting it on your drive to make sure it restores your indicator function etc first. You will get a mileage tamper light on the dash though as mileage won't tie up so then you will need diagnostics to reset that but at least you can drive safely. If it's just around the corner though I would be tempted to let them fit it. 5 minute job plus 10 minutes coding max.

I am almost certain Quarry motors will be able to sort you out with an LCM module. There is not much demand for them as generally very reliable.

OK, I've managed to source a replacement LCM & have fitted it after a chat with my local indy round the corner. And yay it works , all lights back to normal.
I have the tamper light on as expected but also the airbag light :? . Maybe there's a tie in with the 'new' LCM as it wasn't on with the old one & I had the battery disconnected the whole time. Anyway no biggy hopefully, she's going in tomorrow morning to have everything reset & coded .

The LCM needs to be a lower mileage than the car is on as they have to match the two together - the LCM holds the mileage for the car, hence the tamper light. You can add miles but not take them away. Hopefully it's just something that can be reset.

I hope that's not the case. How would anyone selling a used LCM know what mileage the recipient car has on it? I certainly have no idea what mileage my replacement LCM has on it but I presumed the LCM was a backup for the speedo mileage.
My indy round the corner couldn't do the job as he couldn't access the LCM with his software. It's now booked in for 22nd June to be coded by the BMW indy I mentioned earlier. At least I can drive it now :driving: .

 

[oldgitdave]

Will the tamper light go off when the cars miles catch up to that of the module?

I don't think so as the LCM also has the VIN number. Until that's been coded in I'd expect the tamper light would stay on.