Hey all,

2013 R56s, 112k miles, Milwaukee area

My battery fell victim to COVID and my car sat for a couple of months. It deeply discharged and reviving it was a fool's errand. I got the car new and I've never had to replace the battery, so went ahead and got an equivalent AGM and dropped it in and registered it using BimmerCode. Now when I start the car it takes twice as long to turn over and start, and some of the times it will stall out after a couple seconds. My dashboard is lit up like a Christmas tree and the ECM is throwing 28 errors (attached). I've also uploaded a video to show what's going on. I had the ECM replaced in November of 2019 due to what I think is one of the MOSFET's for the ignition coil on cylinder 4 failing.


Definitely not a gearhead, just know how to do brakes and the like. I'm looking for some direction in case I've missed a step registering the battery or if this sounds like another issue with the ECM. Thank you!

 

I deep discharge can cause all sorts of random errors to appear as the control modules go haywire.
Have you tried clearing all the errors?

 

Yeah, I've tried clearing it a couple times. After the first time is when it started to turn over a little bit slower.

 

Well, luckily I was able to keep the ECM that the dealership replaced. Tonight I went and swapped them and I'm getting the same codes/behavior, so that's somewhat good news. Before this I tried clearing the codes again using BimmerLink, but half of them can't be cleared. Also tried Torque, but nothing seems to have reset. I'm going to try a dedicated reader to see if that helps, but I don't have much hope.

 

What happens when you swap the old one back in. What kind of voltage are you getting? Could the battery be faulty?

 

Actually ended up finding the issue, it was the terminal 30g relay down in the foot well panel. I noticed it had been getting warm and picked up a spare. Swapped it in and everything's working properly again.