Uh what's going on here?

[IzzyGray]

Last week I tried starting my car after it sat for 36 hrs. It started normally but an error came on; brake and drive control systems malfunction. Pulled the car our 4 ft but decided to restart it. Started up fine but won't shift into gear and it now says transmission error and won't get into gear. Thought maybe it's an electrical gremlin and went to the trunk to look at battery. For some reason, the blue quick connect cable by my battery was disconnected and I decided to connect it. Started the vehicle and it behaved normally. Didn't have an issue again till today. Car has been sitting longer than my usual 11-12 hrs(18 hrs) and it wouldn't start. It won't even turn over. Almost like its choking. Start hitting pressed, makes a kachick sound and nothing. Systems continue to boot up though. After waiting for the screen to fully load, tried starting and it started but with same brake/drive control error. Turned the car off and back on; did the whole chocking thing. Let computer fully load and it started, this time with only transmission error(won't go in gear). Turned it off for a few mins and turned it back on, fires up as normal and driving normally.

My gut reaction is its electrical but I just got the battery changed about 4.5k miles/2 months ago. New battery is Oem and was coded by an indie shop. Any other thoughts? It's a 2011 e92 DCT. Supercharged and has DCT GTS coding, 82k miles. Rod bearing swapped 4.5k miles ago as well when I swapped supercharger kits.

[IzzyGray]

Oh and Ive driven the car between the first time and now, every single day for about 500 miles with no issues.

[IzzyGray]

Update: just went out to turn her on and now engine malfunction -.- this must be electrical.

[M3lbournE92]

I feel bad for you my man, I hope this problem gets fixed soon!

[Lucrecio84]

could be an issue with your battery, i've heard these cars act really weird when there are voltage issue's

[Scrippy]

Maybe the shop coded the battery wrong. When coding for a battery, your pretty much just telling the car what amperage the battery is. If they put in the wrong value then that would be an issue. Other than that it sounds like a bad ECU holding up the comm on one of the bus lines. The battery could be faulty or your alternator is bad. The alternator could be the likely cause of why you changed the first battery and now it's wearing out your new one.

[IzzyGray]

I just connected the battery tender and its saying it's below 80% so I'm guessing that's probably the culprit. The trip I took today was a short 2 mile trip so I'm guessing it wasn't long enough to recharge the battery and that's why it worsened the symptoms later on today. Sitting for more than 12 hrs must discharge it enough to cause issues. I'll bring it to the indie shop next week to confirm but if she behaves herself tomorrow after overnight tender, then it confirms the suspicion.

[MilehighM3]

You may want to check the battery connections and make sure they're tight. Sounds like a loose connection may be possible judging by your description.

[IzzyGray]

I checked the battery terminals and they seemed snug. However, the red plastic cover is a little loose(it moves around a bit) but I don't think that matters as long as the terminals are tightened to spec, correct?

Woke up today after 10 hours or so of battery tender and it's still less than 80%. Fired her up and no issues. No error, no hesitation. Kinda wary to drive her when battery tender is still showing less than 80% after overnight charging though. Probably fine if i drive a distance but short trips probably gonna drain it again. Argh, was hoping to take her out today.

[THE-FN-MAN]

Has it been confirmed that you must code a new battery? I've read on the forums here that as long as you get a battery with same specs that it isn't needed. Maybe coding isn't worth the trouble?