FUUCKKK, friend tried to install subs in bmw, now wont go into drive!!!

Doubtful anyone is going to have the solution but fuck I thought id at least try… my friend tried to install some subs and an amp in my car tonight and now the fucking thing says tranny/awd/abs and something else malfunction! Motherfucker wont go into drive either!! Obviously he touched the battery in the trunk but also said he had to take the back seats out for something too… Anyone have any ideas on wtf could be going on here???

ONLY thing im thinking is that the battery died and when its dead on these cars it throws all kinda codes/malfunctions, but I think thats hopeful thinking… Charging it now and will see in a few hours.

Charge the battery and check all the grounds. I had a loose ground in my Cadillac, threw a bunch of codes, anti-theft shit, it was crazy.

check grounds , also see if he popped any fuses .

Check your pms…

Serves him right.

Sounds like a fuse issue to me. Is there an override switch? I know on most cars there is a little plastic piece near the shifter you can pop off to override the lock out

Read the owners manual. I would assume he disconnected the battery to install the main power wire to the amp. I have no idea about that particular car, but I wouldnt’ put it past the sneaky german engineers to make the car go into anti-theft or something like that when the battery is disconnected. Could be as simple as some multi step sequence of key on/off/left window down, seat forward, key on bull shit to reset it.

Or not. But honestly check or just call a dealer and ask for advice.

Does it have a stock headunit in it still or an aftermarket one? If aftermarket, did you get the right adapter harness and control box… if applicable? I know the VW’s anti theft and shit goes through the stock head unit so you need a $100 box to suff in the dash. Could be the same with the BMW.

If its the stock HU, where did he tap to get a line level source for the amp input? Check his wiring.

Installing an amp and speaker(s) isnt rocket science at all. I am leaning towards the car is stuck in Anti-theft.

lol, I was lucky, BMW’s are just like Infinitys when they have dead batteries, they throw all kinds of codes and dont run right… I jumped it this morning and all the lights went off and it drives no problem… Mike, its a little more difficult of an install as it has the stock deck with the factory navigation which doesnt have any inputs for subs. We needed some special box that you wire into a harness that gives you outputs for video/subs… I originally thought he spliced a wire that fucked shit up but yeah, was just a dead battery smh lol

Make sure when you get a new battery to go to the dealership and have them install it so they can calibrate your alternator.

Old battery is less then a yr old, just left the doors open and radio on without the car on too long when trying to do the install… Car starts right up everytime after I drove it to work this morning. Didnt know that about having to calibrate the alternator… good to know.

Ah, I didn’t know if it needed replacing or not.
All BMWs made after like, 2002 need to have the alternator calibrated when a new battery is installed. It’s because the alternator “learns” from the battery how good or bad it is, so the alternator will work itself harder to keep the battery optimum. If you don’t calibrate w/ a new battery, it’ll continue working harder and fuck your new battery up. I miss the days of buying a $60 battery from AAP and being good.