[F31-340i]

I've had a very intermittant problem with warnings in my car, usually when the car is warm.

the warnings are dsc, abs, tpms, and low battery - the usual one off warnings that can be linked to failing battery, an abs sensor or ecu issue. I hav also had issues with a red cog (like the famous M5 red cog of death) - which has sometimes led to the car sticking in gear - feels like 4th.

the other day, when it seemed to get hot, it came and stayed, and i had to limp home. this a video of the car doing a steady 50mph. i also lost indicators ad wipers perioducally, sometimes working, then not. it was like an ecu was resetting continually. no idrive either. i did notice the car underbonnet was quite hot (and was heavily loaded at the time for camping with bikes in roof).



it would not reset after key out restart this tiime (which had always cleared the issue before), so i had to leave the car and unpack into the mini. after a hour or so of unloading the car had cooled a bit and was then fine.

several thoughts - i need to get a diagnostic but i'm afraid i will end up in an expensive box replacement escapade that may not solve the issue. i had read that these ecus can develop heat related dry joints - which would match my symptoms, seems like after the last incident its more than an abs sensor.

any thoughts?

car has approx 100k miles and i'm considering a gearbox fluid change anyway. what is the best way to get a new ecu, can they be repaired? i assume a new one from bmw will sting!

[tmarshall57]

I don't know the cause of your specific problem but if ECU related I would definitely trust ECU Testing to diagnose and repair.

[F31-340i]

Originally Posted by tmarshall57

I don't know the cause of your specific problem but if ECU related I would definitely trust ECU Testing to diagnose and repair.

thanks, i've contacted them

[tmarshall57]

One thing I should have mentioned is: read the codes or get the codes read before venturing down what could be an expensive route.

I had similar issues to you (although mine didn't result in the car going into limp mode) and, despite the numerous potential causes (ABS Sensor, battery, steering angle sensor etc), I followed what I thought was a logical route which eventually worked out for me.

See my post here

http://www.e90post.com/forums/showthread.php?t=813999

[F31-340i]

thanks, thats helpful, can you expand a bit on removing the abs hydro unit? is this difficult, soes it involve bleeding?

i guess i would need an inpa to diy it, but looks good value if this is the cause - clearly i need to check codes first.

[tmarshall57]

This post is helpful

http://www.e90post.com/forums/showthread.php?t=600491

The post also includes instructions for removal and replacement of the unit from the manufacturers.

Bear in mind that the unit is on the drivers side of the engine compartment. It was a bit fiddly to remove as I didn't remove the microfilter and the part that the microfilter housing screws on to. Removing this part makes removing the hydro unit a little easier as you can move the brake pipes a little further out of the way. The abs unit is held by three nuts which are a little difficult to see. I loosened the nuts until they were almost free of the stud and then used a grabber/pickup tool

http://www.transtools.co.uk/hand-too...ber-tool-600mm

to finish off the removal of the nuts and ensure they didn't fall down into the bowels of the wing.

If you are not incredibly patient and familiar with VMWare, XP etc the best bet would be to have the codes read by an independent and take it from there. Otherwise there is the danger of wasting a lot of time and money following instincts, rumours etc. It may after all be nothing connected with the DSC/ABS/Hydro unit directly.

Where are you based?

[F31-340i]

Right, just getting around to fixing this. Trouble with having 3 cars is that when 1 breaks there is no rush to fix it.....

These are the codes:



I've sent a mail to ecutuning too.

Initial suspect is it maybe just the battery which I'm going to change as I've had clear warnings on this already, then we'll see.

[JP-76]

Have you checked the charging voltage from the hidden menu?

If it's goes over 15 volts (usually it spikes and then comes back to 13.7-14.6 volts if it's faulty so you have to monitor it for a while) when the car is running, you have a faulty voltage regulator and overvoltage will give you all kind of different warnings that really doesn't exist.

Also you need to get your IBS-cable checked/replaced the same time you change the battery. The IBS-cable is the one that monitors the battery condition and if the charging voltage has been too high, it may have broken the IBS-cable.

I assume that you have AGM-battery? Anyway you need to have the same type/ AH-battery as you did earlier and also the new battery needs to be registered to the car so it knows that it has been changed. Otherwise the battery won't be charged properly.

[F31-340i]

Thanks for the tips, one of those german coded statements does appear to mention voltage too high or similar.

This is the battery, part no is visible. Is this AGS or not; this has been confusing me.



How do you check the IPS cable? Is there a simple continuity check you can do?

I'd seen earlier that the car should be told its a new battery so it charges properly.

[JP-76]

This is normal battery, not agm.

Do you have idrive? If you don't, then you don't have the ibs-cable either.

Check the charging voltage and if it shows faulty, you probably need to visit the dealer, it's not an easy fix.

[F31-340i]

thanks,

I can check charging voltage by just putting a multimeter across the battery terminals with the car idling?

The car has idrive.

Is the fix possible for my local german mechanic, or is it a BMW dealer job? Is it 'just' alternator replacement? Dare I ask how much??

[F31-340i]

Just tested voltage

Car off - battery terms show 11.9v (car has been left for a week or so and not run. battery flattened a few weeks back, and I trickle charged it 2 weeks ago. it seemed reluctant to charge at first)

Car idling - battery terms show pretty steady 14v.

[Skids1]

hi im new to the forum, but it seems that i am having the same problem as yourself after driving my 2006 330d m sport for bout half hour or so or when the car is warmed up i get different faults appearing mostly the dsc failure, dbc failure, run flat indicator failure, and also battery check, then the idrive goes on and off the radio is the same then indicators and window wipers will go on and off themselves also the cars runs really bad the speedometer will drop its as if all the electrics are failing? i also hear a noise comimg from the cd player or idrive as if its trying to load a cd. then when i turn the car off and on it resets itself but it does same thing again soon as i start driving? could you please tell me did you get your car fixed?

also sometimes when this happens it will stick in a gear and transmission fault will come up

[Skids1]

hi just looked at your video and that is exactly what my car is doing? also i had my car put on computer and it is coming up same sort of faults as yours with high voltage beside them

[F31-340i]

hi skids

i haven't fixed it yet - too busy and with 2 other cars its not the priority it should be.

took it to a specialist who read the codes, i've changed the battery - no fix. took it back but the 'specialist' chickened out and said take to bmw.

just plucking up courage for the trip to the stealer. the bill will, i fear, be epic.

[oldbilly]

I too have been having similar problems for the last few weeks and it keeps throwing up dtc/dsc/abs/flat tyre and the dreaded red cog! although when reset the car will run fine, going to have the codes read today will update any results.

[jean019]

I saw a guy having that sort of issue, and it was the voltage regulator.

[JP-76]

Originally Posted by jean019

I saw a guy having that sort of issue, and it was the voltage regulator.

Bingo!

See my first post...

[jean019]

yes I saw it, that's why I told that. It was on a 530d 2006 french forum.
The issue isit can fry some box on the car.

[oldbilly]

Originally Posted by oldbilly

I too have been having similar problems for the last few weeks and it keeps throwing up dtc/dsc/abs/flat tyre and the dreaded red cog! although when reset the car will run fine, going to have the codes read today will update any results.

An update, I had the codes read and cleared on Friday and was going to have them read again later in the week, so drove back home Friday and Yesterday decided to clean the abs speed sensors which took about an hour and its been fine for the last 20 miles no error codes up and none stored usually it throw codes less than 2 miles after 1st start up, drove it 5 miles this morning and nothing at all so hopefully a result.

[F31-340i]

hi oldbilly, how did you clean the sensors?

[oldbilly]

Originally Posted by ///ajd

hi oldbilly, how did you clean the sensors?

the easiest way is to remove a front wheel and you will see 2 cables running down the strut one is the pad sensor indicator and fits into the brake pad the other is the abs speed sensor, identify the abs cable and follow it to the hub where you will see its held in by an alan bolt, undo it and pull it out by the plastic boss, clean any dirt off with brake cleaner, put a little general purpose grease around hole and re-fit taking care not to get any grease on the end of the sensor.