Weird computer behaviour

momosi

New Member
Hi guys,

I am new to the forum and new to the cars. I happens to be that my first car is Audi a2 1.4tdi 75hp Sports edition 2004. So out of nowhere ABS and ESP light came on when ignition switched on and after starting to drive i would get 3 sharp beeps and warning. Now when I stop and restart the engine ESP light dissapears but ABS light stays on. After driving few seconds ABS light dissapears and everything seems fine. However when I stop for more than 5 mins ESP and ABS lights would come back on when ingition on and sometimes it takes few restarts before everything dissapears. Other weird thing is when going on the road I noticed ESP light would start flicker at random points of the journey for like 2-3 sec and dissapears and sometimes it actually re-triggers ABS light to come on and 3 sharp beeps then I have to stop to restart the car and all works fine again for the rest of the journey and third weird thing is when all of this start happening I've noticed that sometimes my remote key would not unlock my car and would literally have to unlock car with key or put key into ignition before it works again ??? I dont recall anything specific happening prior this issue.

Car has been fully serviced before purchase and MOT had 0 faults. Only mod I done myself is fit aftermarket stereo a month ago and took live switched feed from central heating unit with 17amp breaker (Actually stereo cable had slipped so had to break it in twice ... ). Some guys suggested due to this my battery is tripping or fuses ar gone or smth ? could stereo be the cause of triggering all of that ? I done search in forum and some suggest faulty sensor under gear stick ? But I have more symptoms at random occassions literally.

Maybe you guys can shed some light with your experiences and knowledge before i commit to servicing it. ?

Much appreciated
 

Didgesteve

Member
I had the ESP/ABS lights warning for some time and yes the 'Lateral Acceleration sensor' replacement resolved it. I would start by fixing that before going on to any other problems. I don't think the warnings are related to key fob problems or the stereo wiring.
There are a couple of members on the forum who can find you a good second hand sensor. I think I got mine from @A2Steve. It's not a complicated thing to replace.
 
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momosi

New Member
Thank you so much for the info. I was supecting the sensor first from reading the forum but then the key fob thing put me to misery of whats really happening. Stereo actually works/worked fine until now and had 0 problems.. I shall try and swap the sensor and see if it fixes the problem. I dont really care about the key fob as long if it fixes ESP/ABS warnings.. I will check it on the weekend the part that I need as I have no idea.
 

Darren C

Admin Team
Your key fob issue could be as simple as the battery is starting to tell you it needs replacing. Switching the engine off and back on again can sometimes reset things, this would explain why the fault returns. A VCDS scan will help, see here for details of a member who might be close to you and can run one free of charge. Thanks to @Andrew for the concept.
 

beady73

Member
Had the same problem when the voltage regulator on the alternator was wearing out.
IMG_20210702_111418.jpg
 

momosi

New Member
Thanks guys for the input ! I'll check all of possibilities. @beady73 did you had all same symptoms or you refer to key fob issue? Did you change voltage regulator yourself and were is it located ?
 
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beady73

Member
Try and get the VCDS scan as Darren C suggests.
I did not have the problem with my key. I had a the flickering warning light and beeps.
The voltage regulator is bolted and screwed to the alternator under the black plastic cover. I did change it myself.
 

momosi

New Member
Thanks for picture. Just to update I went in for a scan. It's actually ABS sensor (I think drivers side) - electrical circuit fault. Suggests wiring loom needs changing. Any idea anyone where could get replacement part or I heard there is fix kit somewhere ?? should any garage fix it or need going to audi garage ?
 

Providence

Member
When I had that happen to my previous car, I found a local auto-electrician who rejoined the wires and sleeved them all up. Might be the way to go.
 
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