New Battery in 2019 Q5 - Now Showing Errors!
 

We came home from vacation and our 2019 Q5 2.0T wouldn't start - completely dead. Called AAA and they came out and jumped it but then determined the battery had a bad cell. They installed a new one but now when I start the car I get two error messages - one says Side Assist malfunction and the other says Automatic Headlamps malfunction. Also I cannot dim the dashboard at all (stuck on full brightness for some reason). I've read where the new battery needs to be "programmed" which I am not sure they did. AAA did something with the diagnostic port and the tech said the messages would go away. Well they have not and I am waiting on them to come back.

Anyone have any suggestions?

You'll need to scan the vehicle and see what the actual errors are. If you don't have a scan tool like VCDS or OBDeleven, you can't do that yourself and you're left having to hope on whoever your paying to do it for you. Is it something that will self amend and was due to the battery change? Or is it part of why you had a dead battery in the first place? It has nothing to do with not having done the battery adaptation, which you should do.

I was not getting these error messages before. it seems very coincidental that they replace the battery and these error messages start and the gauge dimmer no longer works. The car is four years old (and out of warranty of course). If I read your message correctly, you think the new battery has nothing to do with it?

No, you were bringing up "needs to be "programmed" which I am not sure they did". The lack of updating the battery adaptation is not going to create the problems. That they messed something else up in the physical replacement process, maybe. But again, with a scan log of actual DTCs, it's all random guess as to what's actually up with your vehicle in its present now state.

The battery management system (BMS) should be programmed to maintain a proper charge level and prolong battery life. This would not cause the warning messages you have. Something else has gone wrong here and would not trust AAA to help at all with that. I would have the codes scanned or bring it to a mechanic.

I took the Q5 to an independent shop in Northern Virginia yesterday (never been there before but is highly rated and seems well run). They said it was showing more than the 2 warning messages when they ran diagnostics - more like 55 codes. I called this morning and they suspect a short somewhere and are checking wiring harnesses. Of course the Q5 warranty expired in August. Sigh...

Jump starting a vehicle can sometimes cause damage.
Clear the codes, drive the car, and see which come back. I bet most of those codes are "low system voltage" reported by multiple modules.

That's exactly what I would do. Clear the codes and drive the car. The indy shop is going to charge the op hundreds to "go through the wiring harness". Good luck.

It is not a "short" or a "problem with the wiring harness"....I would find another shop.
After you clear the codes and drive the car a bit, post what all the codes are.

invest in OBD Eleven Pro tool. Scan for DTC codes. Clear. Drive and see if they return. I would also put $ on Low Voltage DTCs.