The Footwell Control Module

[brismith66]

In general, how long should the Footwell Control Module last?

Here's the story: I "owned" a 2011 sDrive30 (about 67k miles) for about a week. Car was absolutely gorgeous. I bought it online, and the retailer had a 7-day moneyback guarantee; I had decided beforehand if my mechanic had any reservations about it, or if it gave me any grief, I'd give it back.

Mechanic said it looked great. Man was I happy.

That night I clicked the lock button on the remote, and the lights didn't blink. I thought that was odd, but it _did_ lock, so I figured I had turned something off or something. The next morning, driving to work, I wondered why it sounded like the door wasn't closed, then noticed the windows weren't working.

I realized also my turn signals weren't working, then my hazards weren't working.

Heartbroken, this counted as grief, and I arranged to return the car, because something was catastrophically wrong with it.

I later learned the constellation of symptoms implied the "footwell control module," and would've been several hundreds (if not a thousand) of dollars' repair.

I understand the FCM can go out without warning, that it might not've even thrown an OBD code, is that right?

I guess my question is: how often does the FCM go out? Is it typical to last 10 years, x number of miles? In other words, is replacing the FCM generally considered routine?

I'd appreciate your input.

Regards,
Brian

[B21]

Sorry to hear your problems with the FRM..

They do not routinely brick themselves..most faults are caused during re-coding and /or due to discharge battery..

That and the rear brake ECU are the most likely units to fail through battery related issues..

[paris1]

It's actually called a body control module, located behind the glove box and yes, it's pretty common. Mine went bad at about half the mileage you've got on yours. A dealer will charge somewhere between $1-1.5k (mine was covered under warranty, so I was just given a rough estimate of what it would have cost back then by my SA). It involves a lot of reprogramming, so it's not really a DIY project (IMO).

[DavesZed]

Originally Posted by paris1

It's actually called a body control module, located behind the glove box and yes, it's pretty common. Mine went bad at about half the mileage you've got on yours. A dealer will charge somewhere between $1-1.5k (mine was covered under warranty, so I was just given a rough estimate of what it would have cost back then by my SA). It involves a lot of reprogramming, so it's not really a DIY project (IMO).

It's actually called the FRM (NFRM on E89's) - Footwell Module, and it's located above the drivers feet, along side the CAS in a plastic cradle (Body Control Module is located on the Fusebox unit).
They do (can) go from time to time, it isn't really common but they can also be repaired with a specialist piece of kit and reprogrammed relatively cheaply. Disconnecting the battery and then removing the FRM too soon (at least 15 minutes) can do it, reaplacing the battery with the key still engaged in the recepticle (having left it there when you disconnected the battery) will also do it. But it's not something that is time/age related really.

[paris1]

OK; I stand corrected. However the symptoms described sound an awful lot like what I experienced when my BCM failed. So what is the difference between a BCM and a FCM?

[DavesZed]

Originally Posted by paris1

OK; I stand corrected. However the symptoms described sound an awful lot like what I experienced when my BCM failed. So what is the difference between a BCM and a FCM?

The JBE (BCM) distributes power to the electric windows (amongst other things) and the FRM (FCM) controls the use of lighting, windows etc, so in your case that could be why it seems similar. The FRM works with the Lin-Bus and CanBus systems controlling how things are operated throughout the car.

[brismith66]

Originally Posted by DavesZed

Disconnecting the battery and then removing the FRM too soon (at least 15 minutes) can do it, reaplacing the battery with the key still engaged in the recepticle (having left it there when you disconnected the battery) will also do it. But it's not something that is time/age related really.

Now when you say "do it," do you mean that's something that'll fry the module?

[bigendbob]

I'm surprised changing battery not suggested, especially a 2011 car.
Remember these cars aren't that common so may have stood a long time before sale.
Talk the seller into a new battery.

[DavesZed]

Originally Posted by brismith66

Now when you say "do it," do you mean that's something that'll fry the module?

In short, yes.
But it doesn't exactly 'fry' the module, it's actually a communication issue with the EEPROM so it stops responding. This can be sorted quite simply with a special piece of kit, but there are a fair few that'll do this service for you on ebay, so probably a lot easier that way. Then once its done it'll start responding again.
Here's a very comprehensive guide on FRM's...
https://bimmerist.com/bmw-footwell-m...es-full-guide/

[brismith66]

Originally Posted by bigendbob

I'm surprised changing battery not suggested, especially a 2011 car.
Remember these cars aren't that common so may have stood a long time before sale.
Talk the seller into a new battery.

I returned the car under their 7-day-moneyback policy (which makes me very fortunate, I suppose, but wow was that car nice). It happens the carfax report said the battery and cable was replaced about 1000 miles before I got it. The battery *wasn't* a BMW-brand. My guess is perhaps when the battery was replaced, it wasn't registered?

One reason I'm curious about all this is that I'd still love to have a Z4, but I wonder whether the FCM was a routine issue.

[brismith66]

Originally Posted by DavesZed

Here's a very comprehensive guide on FRM's...
https://bimmerist.com/bmw-footwell-m...es-full-guide/

Fantastic link; interesting read.

[Tangent]

Originally Posted by brismith66

I returned the car under their 7-day-moneyback policy (which makes me very fortunate, I suppose, but wow was that car nice). It happens the carfax report said the battery and cable was replaced about 1000 miles before I got it. The battery *wasn't* a BMW-brand. My guess is perhaps when the battery was replaced, it wasn't registered?

One reason I'm curious about all this is that I'd still love to have a Z4, but I wonder whether the FCM was a routine issue.

While not registering the battery isn't a good idea, that's solely because it'll kill the new battery quickly. Aftermarket batteries are also totally fine; just get the right type and capacity and register them and it's all good. All batteries are made by just a few manufacturers and then relabeled anyway.

I killed the FRM in my Z4 when I disconnected and reconnected my battery a few times when working on the car so it seems to just be sensitive to the power spikes.

While I wouldn't exactly say the problem is routine exactly, it was common enough that BMW extended the warranty on them to 8 years / 125,000 miles. I was lucky enough to just sneak under that limit when mine died.