[mdebelic]

I have a 2005 330i and the in car systems are doing all sorts of weird stuff. The CD player swtiches to radio when it feels like like it. The idrive button works sometimes and the menu button also does the same. The bluetooth for my mobile phone has stopped working so no more hands free communication.

The car drives fine so no problems with engine management systems. I do leave the key in the ignition for about a minute or more sometimes to test and then there is a battery low warning on the main dashboard display and intrument cluster. I have a couple of questions, is the battery possibly causing these problems? Is the software in the car somehow screwed and how do I update it?

I appreciate any input from anybody regarding these problems or if anybody can give me some feedback of similar problems experienced.

[timmahh]

Sounds like the battery may need replacement soon.. Long story short, some components of the car communicate via a fiber optic network, while others monitor electrical signals/voltages; if your battery is failing and these signals are no longer at a level they should be at, it can cause crazy things to happen. It's not quite like the old days where one wire went to one connection and as soon as it had a signal that item powered on

[mdebelic]

Timmahh

Thankyou for your reply. The car starts fine with the current battery but it seems then it doesn't have enough juice for the other systems, your explanation of how these technical systems are reliant on proper voltage levels is the same understanding I figured would be the case, but thanks for your detailed explanation.

I did disconnect the battery and left it off overnight, no change.

I'll be pissed if I go and buy a new battery and it does not fix the problem, but sometimes you just have to try these things. Hoping this is all it will be.

[ctuna]

http://www.google.com/url?sa=t&rct=j...ggmQNQrEff3wpA

[mdebelic]

hey ctuna thanks for the awesome document link. I have saved it, it will always be handy to have for any future problems and general understanding of the e90 systems.

Well I know it's been a little bit of a while with updating this thread as I have been scouring the net about my problem and talking to the $$$BMW$$$ dealer. OK with the battery situation, I replaced it with a varta brand battery and it did not fix the problem. I did some research with regard to putting a different capacity battery in the car and you do have to tell the computer that you have a different spec battery from the original spec. I have not done this yet, no big deal at the moment.

The first thing that crapped out on my car was the bluetooth and it is the MULF module that is the culprit. The module is located in the boot and I have removed it. The radio works now and the idrive controls do not drop out, no more speaker poping sounds when the in car systems reset themselves. When you remove the MULF the CD player is not going to work because it is now no longer in the MOST fibre network (you can fix this though at the fibre junction box to permantly bypass the MULF).

Whilst talking to the dollarMW dealer about my problems he said that it's probably the MULF module and he suggested that they can bypass it (which I have done) and just put a aftermarket bluetooth kit in my car. The price he quoted me for just the MULF was $2500 plus labour, no wonder he suggested to bypass it. When you replace the MULF it has to be recoded of course like every other bloody module.

The next step for me is to re-solder all the circuit board connections on the MULF and cross my fingers. I did this for the idrive controller when it stopped working soon after I bought the car, fixed, I saved myself $600 and maybe another $200-$300 in labour. Lets hope for the best.

I will post an outcome hopefully within the week.

[Tom K.]

Had the similar "low battery" warning first appear about 18 months ago on my CPO '07 328i E91 purchased in May, 2010. The main symptom was that the Comfort Access would not unlock the doors and the warning icon comes up after one minute when the ignition (but not the motor) is on. The following was done by my dealer - thankfully all under OEM & CPO warranties:

Nov, 2010 - Alternator found to be intermittently charging at 17+ volts and was replaced.

Jan, 2011 - Low Batt warning again. Alternator charging at 15+ volts and was again replaced.

Feb, 2011 - 3rd alternator found to be overcharging. Replaced bad IBS unit and associated battery cable.

The problem returned after 6 months, was present only infrequently for the next 8 months, but was constant by April, 2012. The car continued to start and run fine and the OEM battery tested as good.

May 2012 - Discovered ground fault and fixed bad wire under console. Problem returned after 5 days.

May 2012 - Traced ground fault to JBE. Replaced JBE and so far, so good.

I'm not sure what the MULF module is, but I hope it takes care of your problem.

Good luck.
Tom

[CamelBiscuit]

Originally Posted by Tom K.

Had the similar "low battery" warning first appear about 18 months ago on my CPO '07 328i E91 purchased in May, 2010. The main symptom was that the Comfort Access would not unlock the doors and the warning icon comes up after one minute when the ignition (but not the motor) is on. The following was done by my dealer - thankfully all under OEM & CPO warranties:

Nov, 2010 - Alternator found to be intermittently charging at 17+ volts and was replaced.

Jan, 2011 - Low Batt warning again. Alternator charging at 15+ volts and was again replaced.

Feb, 2011 - 3rd alternator found to be overcharging. Replaced bad IBS unit and associated battery cable.

The problem returned after 6 months, was present only infrequently for the next 8 months, but was constant by April, 2012. The car continued to start and run fine and the OEM battery tested as good.

May 2012 - Discovered ground fault and fixed bad wire under console. Problem returned after 5 days.

May 2012 - Traced ground fault to JBE. Replaced JBE and so far, so good.

I'm not sure what the MULF module is, but I hope it takes care of your problem.

Good luck.
Tom

May 2012 - Smashed all hope that this is an easy fix of just a battery.

[mdebelic]

Hey Tom thanks for your post, all I got to say is "you poor bastard", man what drama you have had to go through. The MULF module is actually the bluetooth communication module, I do not know what the acronym stands for but I do believe it is refered as the TCU/MULF module.

The TCU module is the Telematic Control Module which handles all in car communcations systems. I still have the problem where the speach control button on the stearing wheel still does not work as I believe this is linked to the module I have removed from my car over the weekend.

I have looked in the BMW ETK software for the part number for my MULF module but it cannot find it. When I search by vehicle VIN for the module it says it is a TCU and it looks slightly different to what I actually have in the car. I cannot find any reference to MULF for my VIN.

As for the stereo, I have had my sony walkman plugged in the AUX jack and the stereo has not dropped out once, so I have pulled the right bit out that has been causing me grief. The idrive works fine and navigation works too.

Tom you mention that you had a ground fault to the JBE, what is a JBE?

[Tom K.]

Originally Posted by mdebelic@bigpond.net.au

Hey Tom thanks for your post, all I got to say is "you poor bastard", man what drama you have had to go through. The MULF module is actually the bluetooth communication module, I do not know what the acronym stands for but I do believe it is refered as the TCU/MULF module.

The TCU module is the Telematic Control Module which handles all in car communcations systems. I still have the problem where the speach control button on the stearing wheel still does not work as I believe this is linked to the module I have removed from my car over the weekend.

I have looked in the BMW ETK software for the part number for my MULF module but it cannot find it. When I search by vehicle VIN for the module it says it is a TCU and it looks slightly different to what I actually have in the car. I cannot find any reference to MULF for my VIN.

As for the stereo, I have had my sony walkman plugged in the AUX jack and the stereo has not dropped out once, so I have pulled the right bit out that has been causing me grief. The idrive works fine and navigation works too.

Tom you mention that you had a ground fault to the JBE, what is a JBE?

Actually, since the dealer has taken care of everything, the OEM 5 year battery is still going strong, I've gotten a loaner each time, and (most importantly) my E91 has never stranded me, I can't complain. Also, I have another Bimmer (128i 'vert) to drive.

I'd never heard of a JBE either - it stands for "Junction Box Electrionics" I found this link which explains it:

http://tis.spaghetticoder.org/s/view.pl?1/09/87/85

Hope your problem is resolved for good.

Tom

[mdebelic]

Just an update on my MULF problem, I went over the board and re-soldered the the connector pins and some of the larger surface mount components. Put the module back in the car and no joy.

I have another buddy who is an electronics tech and he said he will have a go at the board. In the meantime I am on the lookout for another MULF. I am wondering if anybody out there knows if I can replace my module with a MULF2 module? Any input on compatible replacements would be great.

[mdebelic]

It has been so long to update the outcome of the problem. I eventually got my MULF module repaired by a technician in Melbourne VIC, his details are

http://autotronic.com.au

(03) 9988 3835 or 0412299034

$400.00 for the repair, and problem solved, bluetooth works fine with iphone. All the other random problems have disappeared as the MULF unit is connected on the MOST bus network.

Saved lots of $$$, I was looking around for a very long time for another second hand MULF and reseaching which part numbers are compatible, was doing my head in a bit, then the risk if it was going to work. 400 bucks, not too much damage and the guy garrantees your module will work, and work it does.

PROBLEM SOLVED