Hey everyone! Actually, my first post on this forum!
So, I have a 2017 Mustang GT (Manual). Someone recently hit the rear of the car. Nothing crazy, had a body panel replaced, and all was good. One day after getting the car back, I start to get the "service advance track" warning, randomly the airbag light, or "hill start assists fault," even the motor bogging for a second sometimes. But it would go away quickly. Then the power steering started to go and now doesn't work at all (this happened over a few days). Once I looked into the issue, I found that the shop had left the battery ground strap completely loose. My question is, could a loose battery strap like that cause actual damage to systems like the EPAS? The controllers must have been experiencing constant voltage fluctuations, which I assume is not good for them.

I will add that I do have 285/40R19 on all four corners. It makes me wonder if the stock EPAS can handle the bigger tires? (my car isn't a PP car) I figure it can.

Any insight is very much appreciated!

 

Well first off welcome to the forum.

All the weird stuff going on could definitely be happening from the missing ground strap. It sounds like some kind of a voltage/electrical issue is going on. I would take it back to your body shop and tell them what is going on. They may have missed other things as well.

I am sure it has nothing to do with the larger wheels/tires. There are plenty of others running bigger than their OEM tires without issue other than maybe rubbing. The wheels/tires should be fine as long as they clear the brakes and don't rub. I assume someone adjusted the ECM to correct your Speedometer when they were installed.

 

I doubt it did any permanent damage but I guess it is possible. Make sure the ground strap is well connected and see if the problems go away. And yeah follow up with the body shop to make sure there is nothing else "loose"