We made the mistake of buying a ‘09 Audi A4 about 2 years ago because it had low mileage (56,000) and seemed to be in excellent shape, and it was a great price. We’ve had nothing but expensive repairs. I do a lot myself but we have to pay often since she’s away in college. The battery died in it last week and I had her drive home and I replaced it. I drove it to the battery shop with a spare key that is seldom used. It started fine for me and my daughter took it back to school. No issues until one day it wouldn’t start. She had someone jump her off and took it to AutoZone to have the new battery tested, everything tested fine. She drove to the store and once again it wouldn’t start. I got it back from her and it has started fine for me every time. I ran a diagnostic on it and had 01128 code passive/sporadic. I went ahead and cleared it since I’m not having an issue. I’ll drive it a few more days and check it again, but in your opinion and experience, does the reset clear up the problem with the immobilizer?
Sometimes yes, sometimes no. If it keeps coming back you likely have an issue you'll need to address beyond just a reset.
That makes sense but I’m looking for a more-often-than-not answer. I can't have my daughter stranded in the Mississippi Delta. I’ll probably just continue to let her drive my wife’s car until I feel I can trust it again. I’ll do some maintenance repairs in the meantime.
As @mod_man mentioned, it really depends! More so with an old German vehicle.
Realise with a 12 yr old Audi, your endless money pit experience is just starting to unfold.
As with any modern German vehicle, that A4 is over engineered with unnecessary electronics which have started to act up, in your case.
Unfortunately, to get an in-depth diagnosis, you’ll need a dealer level scan tool to dive deep into the electronics & isolate the culprit. All of which requires $$$.
If you’re expecting fuss free transportation, the A4 isn’t the car for the job. Let alone for a usually short on $$$ college student.
My advice, if you intend to hold onto the A4, relegate it to beater car status which won’t leave your city limits & don’t fall into the endless money pit trap.
Good luck.
I have an Autel MaxiSys MS906. I do most of my own repairs, when I have time and access. I agree, I’ll probably keep it here and let her finish up school using my wife’s car. I have an emission refresh kit to finish installing and I plan to do a few upgrades with some better-than-OEM parts. Even so, the reset seems to have fixed the issue. I’ve been all over town and out of town once. It has started fine every time. Thanks for the advice.
If a reset did indeed fix it, great! Good luck with the upgrades & keep us posted if you run into the issue again, in future.