Seat Does Not Move and Heat Not Working

makke · 07-04-2022, 05:07 PM

Have looked through a number of threads on the topic both here and on e90, but am still stuck. Driver's seat does not move and heat does not work. The three small LEDs for heat come on briefly then turn off on the center console. Seat does not move forward/aft, up/down, or tilt. Seatback does not work either. Only controls that do work are lumbar and lateral support wings (I believe both of these are inflated?)

The car is a E82 2012 135i. Only codes in INPA are A6E0 and A6E1 on JBBF. A6E0 = Seat heating, driver's side and A6E1 = Seat heating, passenger's side. Interestingly, passenger side is completely OK. Motion and heat all work fine.

Based on other threads, recommended things to check are: fuses, connectors under the seat, the seat control module, and the controls on the side of the seat. Fuses are OK, as are the connectors as far as I can tell. I also disconnected and reconnected them all (at least from the control module) while messing with the module -- see below.

For the module, this is one of those instances where being short is a good thing, as I have the seat pretty high up. After removing the passenger side seat and figuring out how all of the connectors mate to the module (https://www.realoem.com/bmw/enUS/par...&q=61359264974. Doesn't look anything like the picture, by the way. Has 6 connectors going to it.), was able to reach under the driver's seat, disconnect the module, and remove it. (This saved me from dealing with the daunting issue of two of the four bolts that attach the seat to the car being inaccessible without moving a broken seat...) I then swapped the driver's module to the passenger side and the passenger module to the driver's side. The passenger seat still worked, the driver's seat still did not. So it's not the module...

Interesting side note. The modules have identical part numbers, but some of the controls on the passenger side worked backwards after swapping in the driver's side box. To go up, had to push down. Tilt was backwards too. I ended up swapping the modules back to their original locations.

So this leaves me with the controls on the side of the seat, but..., I am not sure that's very plausible given the fact that the heat does not work either and the control for that is on the center console.

So..., what else could it be? Junction Box (JBBF) itself? Seat side controls even with the heat problem? Any suggestions for troubleshooting other than swapping parts?

Thank you.

Lester · 07-05-2022, 01:26 PM

Weird electrical problems are often related to old/ failing battery. Since yours is 10 years old, if your battery is the original, then this is most likely the cause. The computer will randomly shut down modules it views as optional in order to save energy for more critical modules. Also, the ground strap can cause random electrical module problems - if it's corroded.

makke · 07-05-2022, 01:51 PM

Thank you for the suggestions, Lester. The battery hails from May of 2018, so it's a bit over 4 years old. Definitely not a spring chicken, but not the original either. In my E90 325i, I've been averaging about 7 years (and 90K miles) between battery replacements. Have not noticed any weakness starting or any other gremlins until this seat issue. So my initial reaction is that the battery is an unlikely culprit in this case, but I will check the voltage over a span of a few days since that's so easy to do.

Which ground strap are you referring to? I would definitely like to check that.

Thank you again!

Lester · 07-05-2022, 02:35 PM

If you check for recent posts on starting problems, you will find discussions about corroded ground straps, with pictures.

makke · 07-05-2022, 02:54 PM

Got it, thanks. Will inspect.

makke · 07-17-2022, 03:32 PM

Update on the seat situation. Battery, ground strap, etc..., seem OK. To get a 'baseline', checked voltage between the 'large' holes on the main connector to the passenger seat, found 12V between pins 4 and 8 and 4 and 13. Could not check the other pins as they are tiny and I don't have anything small enough to stick in there. Checked the same pins on the driver's side and, nada. So, yes, the seat is not getting power, even though lumbar and lateral wings still work.

Tried to find a wiring diagram but only source I could locate is here: https://www.bimmer-service.com/. The file is 2GB ISO image that I could not decode. If someone has a PDF for a 2012 E82, or can provide some instructions as to how to decode the ISO, I would be very grateful. Will post a separate thread with a request.

In the meantime, am I correct in understanding that the next upstream box is Junctionbox Electronics, below the fuse panel behind the glove box? Is there an electronic way to troubleshoot this box? Any ideas other than replacing it at this point? (I understand that the replacement will need to be coded to the VIN.)

Thank you.

makke · 09-06-2022, 04:33 PM

Apologies for a belated update. Ended up needing to take the car to a mechanic for another issue. The problem with the seat turned out to be missing fuse 46. I have absolutely no idea how a fuse went missing all of a sudden, the socket is nice and tight, but somehow it did. I only recall pulling one fuse, 45, in that location when checking whether any were bad. A complete head scratcher...

Since not all fuses listed on the fuse diagram are populated for any given car, I had no way of knowing that one was missing without either a wiring diagram or the experience of a mechanic who has worked on thousands of cars...

Thank you again for trying to help.

07-04-2022, 05:07 PM	#1
makke Private 24 Rep 75 Posts Drives: 2006 325i, 182K and counting Join Date: Sep 2017 Location: MD iTrader: (0)	Seat Does Not Move and Heat Not Working Have looked through a number of threads on the topic both here and on e90, but am still stuck. Driver's seat does not move and heat does not work. The three small LEDs for heat come on briefly then turn off on the center console. Seat does not move forward/aft, up/down, or tilt. Seatback does not work either. Only controls that do work are lumbar and lateral support wings (I believe both of these are inflated?) The car is a E82 2012 135i. Only codes in INPA are A6E0 and A6E1 on JBBF. A6E0 = Seat heating, driver's side and A6E1 = Seat heating, passenger's side. Interestingly, passenger side is completely OK. Motion and heat all work fine. Based on other threads, recommended things to check are: fuses, connectors under the seat, the seat control module, and the controls on the side of the seat. Fuses are OK, as are the connectors as far as I can tell. I also disconnected and reconnected them all (at least from the control module) while messing with the module -- see below. For the module, this is one of those instances where being short is a good thing, as I have the seat pretty high up. After removing the passenger side seat and figuring out how all of the connectors mate to the module (https://www.realoem.com/bmw/enUS/par...&q=61359264974. Doesn't look anything like the picture, by the way. Has 6 connectors going to it.), was able to reach under the driver's seat, disconnect the module, and remove it. (This saved me from dealing with the daunting issue of two of the four bolts that attach the seat to the car being inaccessible without moving a broken seat...) I then swapped the driver's module to the passenger side and the passenger module to the driver's side. The passenger seat still worked, the driver's seat still did not. So it's not the module... Interesting side note. The modules have identical part numbers, but some of the controls on the passenger side worked backwards after swapping in the driver's side box. To go up, had to push down. Tilt was backwards too. I ended up swapping the modules back to their original locations. So this leaves me with the controls on the side of the seat, but..., I am not sure that's very plausible given the fact that the heat does not work either and the control for that is on the center console. So..., what else could it be? Junction Box (JBBF) itself? Seat side controls even with the heat problem? Any suggestions for troubleshooting other than swapping parts? Thank you.
	Appreciate 0 Tweet Quote

07-05-2022, 01:26 PM	#2
Lester Brigadier General 295 Rep 3,350 Posts Drives: Join Date: Oct 2007 iTrader: (0)	Weird electrical problems are often related to old/ failing battery. Since yours is 10 years old, if your battery is the original, then this is most likely the cause. The computer will randomly shut down modules it views as optional in order to save energy for more critical modules. Also, the ground strap can cause random electrical module problems - if it's corroded.
	Appreciate 0 Quote

07-05-2022, 01:51 PM	#3
makke Private 24 Rep 75 Posts Drives: 2006 325i, 182K and counting Join Date: Sep 2017 Location: MD iTrader: (0)	Thank you for the suggestions, Lester. The battery hails from May of 2018, so it's a bit over 4 years old. Definitely not a spring chicken, but not the original either. In my E90 325i, I've been averaging about 7 years (and 90K miles) between battery replacements. Have not noticed any weakness starting or any other gremlins until this seat issue. So my initial reaction is that the battery is an unlikely culprit in this case, but I will check the voltage over a span of a few days since that's so easy to do. Which ground strap are you referring to? I would definitely like to check that. Thank you again!
	Appreciate 0 Quote

07-05-2022, 02:35 PM	#4
Lester Brigadier General 295 Rep 3,350 Posts Drives: Join Date: Oct 2007 iTrader: (0)	If you check for recent posts on starting problems, you will find discussions about corroded ground straps, with pictures.
	Appreciate 1 NewDaddyDee87.50 Quote

07-05-2022, 02:54 PM	#5
makke Private 24 Rep 75 Posts Drives: 2006 325i, 182K and counting Join Date: Sep 2017 Location: MD iTrader: (0)	Got it, thanks. Will inspect.
	Appreciate 0 Quote

07-17-2022, 03:32 PM	#6
makke Private 24 Rep 75 Posts Drives: 2006 325i, 182K and counting Join Date: Sep 2017 Location: MD iTrader: (0)	Update on the seat situation. Battery, ground strap, etc..., seem OK. To get a 'baseline', checked voltage between the 'large' holes on the main connector to the passenger seat, found 12V between pins 4 and 8 and 4 and 13. Could not check the other pins as they are tiny and I don't have anything small enough to stick in there. Checked the same pins on the driver's side and, nada. So, yes, the seat is not getting power, even though lumbar and lateral wings still work. Tried to find a wiring diagram but only source I could locate is here: https://www.bimmer-service.com/. The file is 2GB ISO image that I could not decode. If someone has a PDF for a 2012 E82, or can provide some instructions as to how to decode the ISO, I would be very grateful. Will post a separate thread with a request. In the meantime, am I correct in understanding that the next upstream box is Junctionbox Electronics, below the fuse panel behind the glove box? Is there an electronic way to troubleshoot this box? Any ideas other than replacing it at this point? (I understand that the replacement will need to be coded to the VIN.) Thank you.
	Appreciate 0 Quote

09-06-2022, 04:33 PM	#7
makke Private 24 Rep 75 Posts Drives: 2006 325i, 182K and counting Join Date: Sep 2017 Location: MD iTrader: (0)	Apologies for a belated update. Ended up needing to take the car to a mechanic for another issue. The problem with the seat turned out to be missing fuse 46. I have absolutely no idea how a fuse went missing all of a sudden, the socket is nice and tight, but somehow it did. I only recall pulling one fuse, 45, in that location when checking whether any were bad. A complete head scratcher... Since not all fuses listed on the fuse diagram are populated for any given car, I had no way of knowing that one was missing without either a wiring diagram or the experience of a mechanic who has worked on thousands of cars... Thank you again for trying to help.
	Appreciate 0 Quote