: Body Control Unit?
Apr 14th, 2012, 04:54 PM
Hi, im in the middle of fixing a problem on my 2001 mini one. I got an auto-electrician round to have a look and after looking at the fault codes he said that he 'thinks' the problem is a faulty control unit. However he wouldnt check the wires from the ecu, abs module or instruments to see if there was a break.
My question is would the body control unit cause the speedo not to work and the abs light and handbrake light stay on and also constantly turn the temp gauge off and on? These are the problems that i have and 95% of the time they are not working. I have seen the list showing what the unit controls and i cant see anything connected with my problems and my electric windows, central locking, etc are working perfectly fine.
I was hoping to check the wires going from the modules to see if there's a break but its hard to find anywhere online with the diagrams, i only have the abs module one so far.
Thanks for any help :) The abs module/pump has been changed by the way and all four wheel sensors are showing up as working.
Apr 14th, 2012, 05:48 PM
MINI WDS (Wiring Diagram System) online access is now available for diy MINI owners here:
WDS BMW Wiring Diagram System - Model Selection (http://www.bmw-planet.com/diagrams/release/en/index.htm)
Click on R50 (Mk1) or R56 (Mk2) MINI to start searching. :)
As you may know many electrical problems can be caused by the BC1, especially if damp or corrosion gets in. The Mini's modern 'network bus, wiring system means many items can be affected even if not directly controlled by the BC1.
More info here:
The BC1 (Body Control Unit) - Forums (http://forum.minicooper.org/showthread.php?t=9924)
Apr 15th, 2012, 07:49 AM
Thanks for the wiring diagrams, il have a look at that now.
I've read that 2nd link plenty of times now but there's no mention of abs or speedo on there so im guessing that it cant be the bc1 at fault?
Apr 15th, 2012, 07:53 AM
Every option i click on the diagram website comes up with error :( does it work on your computer?
Apr 15th, 2012, 09:02 AM
If you mean the wiring diagrams?................yes, works ok for me.
You may need to download Java add on below to view properly, as that comes up when the website first loads on my computer?
What is Java? (http://www.java.com/en/download/whatis_java.jsp)
Apr 18th, 2012, 09:23 AM
The diagrams are working for me now cheers :)
It's looking really complicated though lol. It's looking like the ecu and the abs module are going directly to the instruments so it maybe a broken wire connecting them.
The auto electrician said that he thinks it's the body control unit, will this be called the general module control unit? It is showing this going straight to the instrument cluster so he maybe right.
How am i going to check these? Im thinking these wires maybe to hard for me to test. Is it as simple as getting to the instrument module and finding which number wire goes to the other modules and seeing if there's a break? Or am i best getting that electrician back down? :(
Apr 18th, 2012, 11:56 AM
It is difficult to check this stuff without diagnostics, wiring is a shared network for signals to various other modules around the car......BC1/Body Control Unit and General Module Control Unit are usually different terms for the same unit........there is also a module in the speedo/instrument cluster I believe which could be at fault.......or it may just be something simple like a bad/corroded earth connection to the body or broken wire somewhere!
Apr 23rd, 2012, 04:35 PM
I've just rang the electrician and he doesnt seem to want to look at it more and says that itl be very unlikely that it's the wires.
He says that he thinks it will be the control unit but isnt sure enough for me to get it replaced. The problem was something like there was no connection from that unit to the diagnostic machine so that's why he's saying it's that, or at least something to do with it.
Im really unsure what to do tbh, i can either go to bmw and get one of these units and get it coded (i read online it's around £500...?) or i could take it to bmw to get it checked but without much money im not sure what the procedure would be, would they check it out and let you know what's what before fixing it?
What would you be checking firstly? I know that the control unit goes to the instruments and so does the ecu. Im really stuck what to do next :(
Apr 23rd, 2012, 06:00 PM
I believe BMW Main Dealer Diagonostic check is normally about £80 before they actually rectify any fault. Maybe worth enquiring exactly what info you will get.
Also worth removing the BC1 and checking for damp/corrosion, see link above.
Also may be worth asking 1320 below for advice who have Mini Diagnostics and are good independent Mini specialists and a Mini2 sponsor:
MINI Servicing - MINI Repairs - MINI Service (http://www.1320.co.uk/topic/22-servicing-repairs.aspx)
If it turns out to be the BC1 reconditioned and used units are available from links below far cheaper (but ask about the coding to your Mini - or BBA-Reman can also check/repair your own unit)
MiniCooperBodyCtrl MiniCooperBodyCtrl (http://www.bba-reman.com/catalogue/DetailedProduct.aspx?DetailedProduct=1414)
Mini Body BC1 Module R50 ALL METAL - Mini Spares UK (http://www.minisparesuk.com/product-details/433-Body-BC1-Module-R50-ALL-METAL/)
Mini Body BC1 Module R50 PLASTIC - Mini Spares UK (http://www.minisparesuk.com/product-details/431-Body-BC1-Module-R50-PLASTIC/)
May 9th, 2012, 10:23 AM
I finally took the control box out to have a look at the connections for water damage.
There's a green plug and a smaller white plug on the bottom of the box. I've had a look at the wiring diagrams and am i right in saying that one of these will control the instruments and the other will control the electric windows/etc?
I didnt get round to taking the white plug off because i didnt want to snap it off and was akward to get to it but when i looked at the green one it looked a bit weird.
There was no sign of any corrosion or orange or anything like that but on the pins there was somesort of 'gel' on them. This was on both ends of the connections and im pretty sure it shouldnt be there. Whether it is water and has somehow reacted to the metal and set like that or if the previous owner had a similar problem and tried to make it more waterproof. Has anybody had anything similar? The thing that is on my mind is that this problem first came when i gave the car it's first jet wash so maybe the water got in when i did that. The car is a 2001 and doesnt have the cover to protect it.
If you think this is my problem, how do i dry it out? Is it a case of spraying it in wd40 and getting the hairdryer out? Im aware that it could of got into the actual unit and damaged it but i need to know for certain before changing it as it's pretty expensive.
These are a few quick pics to show what i mean, if this plug definetly controls the instruments then im pretty sure that it will be the cause.
Actually scrap that, i dont have enough posts to post the pictures lol.
May 9th, 2012, 11:55 AM
If you look back to my previous link below green connector is X332 and controls listed items below I would think:
The BC1 (Body Control Unit) - Forums (http://forum.minicooper.org/showthread.php?t=9924)
INI BC1 Connections List
X332 20 pin (green) "A"
X253 54 pin (black) "B"
X254 54 pin (natural) "C"
X255 54 pin (blue) "D"
1 Terminal 30 Fuse F37
2 Passenger window open Passenger door window motor
3 Terminal 30 Fuse F1
4 Passenger window closed Passenger door window motor
5 Ground Chassis ground
6 Driver window open Driver door window motor
7 Terminal 30 Fuse F19
8 Driver window closed Driver door window motor
9 Left high beam Left headlight
10 Ground Chassis ground
11 Ground Chassis ground
12 (not used)
13 Right high beam Right headlight
14 Terminal 30 Fuse F14
15 Left low beam Left headlight
16 (not used)
17 Terminal 30 Fuse FL12
18 (not used)
19 Right low beam Right headlight
20 Terminal 30 Fuse FL8
Some people have had success by placing the BC1 in a warm 'airing cupboard' overnight and/or using a hairdryer without opening the sealed module. BBA-Reman are usually quite helpful for advice on checking/reconditioning your own module to make any Dealer re-programming unnecessary when re-fitting I think.
May 9th, 2012, 01:57 PM
Hmm doesnt look like that connector would be at fault then because none of those electrics are playing up.
How does the unit come out of the car? I took off one 10mm bolt so i could twist it around to have a look but couldnt seem to find what else was holding it on. Is it safe to take the module out and for it not to lose any information?
Thanks again for your replies.
May 9th, 2012, 02:10 PM
Just re-read your link and seems that the guy on the bottom post got a new unit without going to bmw and a place near me can program it in so that's not too bad :) Just need to firstly see if that's the cause or not though.
May 9th, 2012, 07:26 PM
Yes, you can remove without loosing programmed info, same as when disconnecting battery. Can't remember number of fixings, maybe also a clip? the BMW diagram shows the nut no.5 here as in the photo:
RealOEM.com BMW R53 Cooper S BODY CONTROL UNITS AND MODULS (http://www.realoem.com/bmw/showparts.do?model=RE32&mospid=48020&btnr=61_1500&hg=61&fg=25)
May 10th, 2012, 12:20 PM
Thanks, you've been a great help. Hopefully il get this problem sorted soon lol
May 26th, 2012, 11:53 AM
Just thought id update this for future reference for people.
Somebody on here recommended Northwest BM in Horwich, Bolton. So i gave them a ring and took the car down to get it checked out. After an hour or so they gave me a ring and told me it was the Instrument module at fault and you have to buy them new and get them programmed (same as the BC1s). The guy was very helpful and told me exactly what they tested, etc. It's costing me £635 for a brand new module, fitting and programming and the labour for checking the car which i didnt think was too bad really.
Il be going down next week to have it fitted and hopefully it will have cured the problem. If this works then il highly recommend these guys, really usy place but there's plenty of ramps and mechanics to get the job done quickly and they are just a fraction of the price BMW would charge :)
Jun 4th, 2012, 06:07 PM
Thought i'd update this again :rolleyes:
I went down to get the car sorted and after looking at the car all day the guy couldnt get the new dials to program! He spent ages trying to find out why and was really struggling. The wiring was all checked and even though it had been repaired before it's fine now, the BC1 was tested and was fine. I told him that i had changed the abs module before and he says that's the reason. The wiring inside it didnt add upto the right amount of volts, the two wires were meant to read 5 together but it was over 6 and he said that it would of fried the old dials.
This is making sense though as with the old abs module i used to be able to clear the faults on the code reader and when i fitted the new one that was when the instrumentation and error with the ecu codes came up. I have it booked in this week so i can bring the old one down to check to see if it'll work. Im guessing that it will work and he'll be able to set the dials up but i know that a mile down the road it's going to break again. At least that's the problem that the car has.
My question though is can i buy a reconditioned unit and be guaranteed it'll work? Im not wanting to go to BMW and pay over a £1k for a new one :(
Jun 5th, 2012, 10:01 AM
I have used BBA-Reman before for re-conditioned modules on other cars and a Mini steering pump and they have been ok and they also replaced one throttle body module (Mercedes) for me which went faulty inside their 2 year warranty period.