CAN bus problem very strange pls help

hi guys , i have an odd problem , this is what happend :

de tacho goes flat while driving , al indicators of gear blink , have a lot of faults in the cluster like :

power steering
drive train control fault
no gear selection possible
etc..

the car goes into 3th gear i think , almost al lamps in the cluster light up ,
when i start again it will be fine for a while , but it comes back , i allready changed the transmission seals from the connector wich i first thougt where the problem was , but it wasn't .

now i don't know it anymore and hope very much any of you could help , i have several faults
al can-bus related !

see this video i took when it happend :



tnx in advance

(car is a 02 745i)

This points to an alternator or battery problem. Start by replacing the battery first or having someone check to make sure the alternator is working properly.

could such thing really be a battery isseu ? can i program a new batt with my snap on solus ultra ? haven;t found the option yet !

when all of these modules start reporting faults at the same time it is usually power related. If you battery is pretty old thats a good place to start. The CAN bus and all the other BUS systems in the car are connect to the central gateway module called the ZGM which basically is a hub that connects all the different bus systems together and allows them to communicate. If its not your battery then the next thing I would check in the ZGM module.

I am giving you the most easy and logical place to start your troubleshooting before you go spending money on things that you dont need. A battery is something you would have to change after a few years on this car anyways so why not start there.

I dont know anything about registering the battery with the tool that you have. Most people on here use INPA or Dashsoft..both have the ability to register a battery. If you plan on troubleshooting the car yourself then do a search on here for INPA. There are lots of threads with where to get cables, software etc.

Thanks for the reply , i think you might get it just right since my battery was dead a week ago , charged it and has ok since then , but it is old ans replacing it would be the right thing anyway , ordered it , and place it tomorrow . keep you posted !

while driving, your alternator should be the source for electricity... i had this same prob...

under warranty dealer replaced alternator.... symptoms went away and came back

they then changed "intergrated supply (module: 121099)

as well as 322 IPS which is a position sensor fro tranny


says test for DME faults - all faults led to "IVM powering up modules" they checked power and ground to IVM had voltage drop Replaced IVM.

if alternator is bad, may not be cahrging battery correctly... which can damage battery

i had SAME error! on LCD of MMI it said P,D,R, 1,3 gears available lol driving 40 in 3rd

Today changed my battery , and programmed it , no change , all the faults i get are can bus faults in pcm/tcm/abs/dcm etc . Bus out or timed out faults any suggestions , i'm stuck at this point

try my suggestion http://www.flickr.com/photos/2810754...7625279270417/ - is IVM

i took the whole case apart , couldn't find anything wet or corroded , looks like new in there .
Isn't there a known solution for this ? i think 1 module is grounding the ptcan bus or something , or a wire is broken somewhere , but there are o lot of them !

if you r talking about my suggestion, does need to be wet or corroded..... just faulty lol... the pics are not mine, they are kiefs..... his may have been, i dunno... that is just location of IVM, which dealer replaced for my same symptoms///

That is the Generator - he make to much voltage like 17V or 18 V --see in failer discreptin samtimes in EGS or DSC you se the Voltage on Failer

alternator - like i said b4 - check that.... the diodes on mine blew.... it made power for the car but it was fluctuating and glitched the systems........


question for you and please be honest (lol you wont get in trouble) - do you drive your car hard...? do you smash the gas in first gear... do you do burnouts? these high revs WILL kill your alternator...it wasnt meant for that kind of application.... this car is for cruising and not racing.... just FYI

i'll check it asap and keep you posted !

i am a sporty driver !

Originally Posted by Franky20v

i am a sporty driver !

Originally Posted by Franky20v

hi guys , i have an odd problem , this is what happend :

de tacho goes flat while driving , al indicators of gear blink , have a lot of faults in the cluster like :

power steering
drive train control fault
no gear selection possible
etc..

the car goes into 3th gear i think , almost al lamps in the cluster light up ,
when i start again it will be fine for a while , but it comes back , i allready changed the transmission seals from the connector wich i first thougt where the problem was , but it wasn't .

now i don't know it anymore and hope very much any of you could help , i have several faults
al can-bus related !

see this video i took when it happend :



tnx in advance

(car is a 02 745i)

i got a similar situation, when technician reset the system via OBD, my car have strange things like, light turns on when it wants, alarm arm or disarm when system wants, it was very sterange, technician said me that maybe it was alternator or battery, but when he reset the system, all came back to normality, so, i recommend you try to reset the entire system first.