total car electronics failure
hello everyone,
today i had a complete electronics failure of my 2011 A6 3.0 TDI quattro (180 KW) while driving around town... it started by simultaneously displaying several errors (TPMS, ESP, air suspension, ACC and braking guard failure). i turned off and started the engine again and this cleared the errors (this has happened a few months before), however they have reappeared soon after and progressively more systems failed.
i have done an autoscan with vcds (attached autoscan 1), tried to clear the errors and rescan after a couple minutes (autoscan 2). can please someone help me locate the fault, as it seems to me that most of the systems point to and ABS (sensor???) failure.
in the meantime things have gotten worse, there are intermittent brake failures, car speed indication does not work, rear view camera and parking sensors are on and off, and even MIL and glow plug indications have both turned on.
the car idles at 1000RPM, the steering wheel is very heavy and the air suspension is completely nonfunctional (like riding a bike).
i have read about similar situations being located as a problem with an ABS sensor (or the bearing connected to it), however i'm confused by the engine errors displayed. i would greatly appreciate your help, as this seems like a major malfunction to me!?!?
thanks
p.s. other than the mentioned problems, car runs fine, there is no jerking, hesitation that i have noticed and the brakes seem to work with normal stopping force.
Re: total car electronics failure
Just had the same happen to my Volvo C70. Wipers on when switch off and dash lit up like a Christmas tree. RAC took it to a specialist on Monday, he reset everything and says he can’t repeat the problems.
I know it’s a long shot but do you think it’s the prolonged heat? I’ve seen a few similar problems reported.
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Re: total car electronics failure
A dodgy battery can wreak havoc on electronics. Might be worth replacing if it’s as old as the car.
There’s been a few posts on here about dodgy electronics and new battery sorted it.
Re: total car electronics failure
@JonathanK
I don't think it's prolonged heat, since i have only driven the car for 10 minutes when this happened... The car has been in the sun all day but... Could really this be the problem? I also tried clearing the DCTs and they appeared again...
@A6S
I have heard that the battery could cause all sorts of electronic problems. To be honest i don't know how old the battery is since i only recently bought the car and I'm not the first owner. If the battery IS the problem, would connecting the car to a charger eliminate the errors (at least temporarily)?
Re: total car electronics failure
Problems with old batteries is cranking power. When you start the car the starter motor saps all power and leaves nothing for rest of the cars electronics. Essentially sending them all in a hissy fit as their startup routine is affected. Like turning off your pc mid boot.
Battery is worth trying as it’s cheap compared to everything else.
Re: total car electronics failure
Quote:
Originally Posted by
vladomkd
today i had a complete electronics failure of my 2011 A6 3.0 TDI quattro (180 KW) while driving around town...
As all your faults happens during driving, I think, it's not related to the battery. I had similar issues with my former A6/C6 which was equipped with an immobiliser system. Sometimes this system activated and this caused the above mentioned problems, system failures and other problems were displayed and the car acted just like a junkyard competitor. When that system was disabled, everything became fine.
So, IMHO it's REALLY possible that a damaged CAN bus related system can cause these problems. Probably you should check that sensor first.
Re: total car electronics failure
Quote:
Originally Posted by
AT.
As all your faults happens during driving, I think, it's not related to the battery. I had similar issues with my former A6/C6 which was equipped with an immobiliser system. Sometimes this system activated and this caused the above mentioned problems, system failures and other problems were displayed and the car acted just like a junkyard competitor. When that system was disabled, everything became fine.
So, IMHO it's REALLY possible that a damaged CAN bus related system can cause these problems. Probably you should check that sensor first.
I was under the same impression, besides i haven't noticed any difficulty in cracking the car (as expected when the battery is empty), although i see the validity of A6S' opinion as well...
I will take the car for diagnostics hopefully today and will see what would their opinion be...
Re: total car electronics failure
ok, quick update dudes...
i took the car to a local vw/audi mechanic. he had it scanned and determined that the ABS ECU is unreachable. took the ABS ECU out, checked that there is voltage supply, glared at it for a minute and plugged it back in.
all of the sudden the ABS module became responsive, he cleared all errors except TPMS, ESP and air suspension (which cleared after a short drive and engine restart).
so far it seems that the problem is resolved, but i will restrain from traveling far in the following days/weeks just in case this bullsh*t reappears... all in all seems like a loose contact or some sort of contact corrosion/oxidation, which is strange considering the inside and the contacts of the ABS ECU (there are a million of them btw, for those that haven't seen the inner face of the ABS ECU) seemed perfectly clean, with no signs of water/mud ingress...
anyways, thanks to everyone for the constructive suggestions :)
Re: total car electronics failure
Re: total car electronics failure
well, unfortunately i wasn't as lucky to be a loose contact. all of the problems reappeared today when i started the car. i unplugged the ABS connection again, plugged it back in, cleared all errors and all is fine at the moment (again).
at this point i'm beginning to be certain that it's the ABS ECU warning me it's about to completely die very soon. probably unplugging the cable resets the ABS electronics, but this seems to be a short term remedy.
has anybody had similar situation? can the ABS ECU be dismantled to check if it's something obvious (e.g. a faulty capacitor)?