Battery Change - Car UNDRIVEABLE

[Imperialgrunt]

So my battery randomly died when I was washing my car. I ran out and bought a new one. When I tried installing it, I accidentally hooked the battery up backwards since it was night and I was not paying attention. My car alarm shot on as soon as I connected both terminals, and I quickly unplugged the battery afterwards. Both cables were pretty hot. I waited a few minutes, and flipped the battery, connected the right terminals, and the car turned on just fine. OR SO I THOUGHT.

My car has NUMEROUS error codes on now. And my power steering doesn't work. The steering wheel is VERY VERY HARD to turn, that I barely made it home from the car wash. There is a transmission code. Adaptive light code. And a code that my battery is not being charged, which is what really scares me. I drove the car home which is about 5.5 miles, and none of the codes went away, nor did my steering loosen up. And when I check my battery status through my OBD11 it does not show the battery being charged.

Anyone recommend what I should look at first? Fuse box? Blown fuses?

This is for a 2015 Volkswagen GTI Autobahn.

 

[StorableComa]

Fuses would be the first thing to go through.
https://www.autogenius.info/volkswagen-golf-mk7-2012-2018-fuse-box-diagram/

 

[Imperialgrunt]

Fuses would be the first thing to go through.
https://www.autogenius.info/volkswagen-golf-mk7-2012-2018-fuse-box-diagram/

Thank you for the diagram. Would you happen to know as to what fuse correlates to the power steering, and or alternator fuse?

I checked all my colored fuses and the only blown fuse I see is F19, which looks like it relates to "Wiper motor control module -J400- " "Windscreen wipers (front)"

 

[IWMTom]

So my battery randomly died when I was washing my car. I ran out and bought a new one. When I tried installing it, I accidentally hooked the battery up backwards since it was night and I was not paying attention. My car alarm shot on as soon as I connected both terminals, and I quickly unplugged the battery afterwards. Both cables were pretty hot. I waited a few minutes, and flipped the battery, connected the right terminals, and the car turned on just fine. OR SO I THOUGHT.

My car has NUMEROUS error codes on now. And my power steering doesn't work. The steering wheel is VERY VERY HARD to turn, that I barely made it home from the car wash. There is a transmission code. Adaptive light code. And a code that my battery is not being charged, which is what really scares me. I drove the car home which is about 5.5 miles, and none of the codes went away, nor did my steering loosen up. And when I check my battery status through my OBD11 it does not show the battery being charged.

Anyone recommend what I should look at first? Fuse box? Blown fuses?

This is for a 2015 Volkswagen GTI Autobahn.

Any "control module faulty" faults? I'd expect to see at least something fried from reverse polarity.

Have you coded the new battery in to the system?

 

[Imperialgrunt]

Any "control module faulty" faults? I'd expect to see at least something fried from reverse polarity.

Have you coded the new battery in to the system?

I will check the error codes in the morning. I scanned and reset them all, but haven't noted any of them yet.

As far as the battery coding...I just found out a few minutes ago that coding is required to change the battery? Some posts say that coding is only required for the European GTIs, and that the American models you can just slap them in there and go, but I can't validate this information yet.

 

[IWMTom]

I will check the error codes in the morning. I scanned and reset them all, but haven't noted any of them yet.

As far as the battery coding...I just found out a few minutes ago that coding is required to change the battery? Some posts say that coding is only required for the European GTIs, and that the American models you can just slap them in there and go, but I can't validate this information yet.

Sorry, yes, I do keep forgetting about the NAR differences. Do you have a battery monitoring module attached to the negative pole of your battery? If so, it needs coding. If not, it doesn't.

 

[IWMTom]

Thank you for the diagram. Would you happen to know as to what fuse correlates to the power steering, and or alternator fuse?

I checked all my colored fuses and the only blown fuse I see is F19, which looks like it relates to "Wiper motor control module -J400- " "Windscreen wipers (front)"

View attachment 191952

See those fused linkages at the left hand side of your photo? The big metal things?

Alternator is SA2 (second from the left) and is a 400A fused linkage.

Power steering is SA3 (two along to the right) and is an 80A fused linkage.

 

[Imperialgrunt]

Sorry, yes, I do keep forgetting about the NAR differences. Do you have a battery monitoring module attached to the negative pole of your battery? If so, it needs coding. If not, it doesn't.

Yea, my vehicle does not come with any modules on the negative terminal. So I think I'm safe on that part.

As far as the fused linkages go, how can I inspect those to see there are issues with them? I've never dealt with this sort of issue before, and have no experience with wiring and fuses.

 

[IWMTom]

Yea, my vehicle does not come with any modules on the negative terminal. So I think I'm safe on that part.

As far as the fused linkages go, how can I inspect those to see there are issues with them? I've never dealt with this sort of issue before, and have no experience with wiring and fuses.

It should be fairly obvious if one has blown, given how much current would run through beforehand!

Afraid I'm not sure either as I've never had trouble with one before. Give it a close inspection and look for any scorch marks I suppose.

 

[PRRGG1]

Scary stuff. The cables on most vehicles are of such a length that you can't set the battery in place backwards and make connections.

 

[KevinC]

Throwing a bunch of error codes after a battery swap is normal, even without the polarity clusterfarkle happening. Those will just clear on their own if there wasn't more significant damage done someplace.

 

[Imperialgrunt]

So I’ve checked the fuse links right now and cannot visually tell of any scorch or burn marks. It all looks normal.

I’ve checked the engine and dash fuses, and they are all still solid except the F19 fuse, which I’m going to go replace now.

However, the brand new battery I bought yesterday is completely dead after one night. The engine nor any electronics are turning on in the car.

 

[Imperialgrunt]

Scary stuff. The cables on most vehicles are of such a length that you can't set the battery in place backwards and make connections.

I guess they couldn’t engineer for stupidity...

Throwing a bunch of error codes after a battery swap is normal, even without the polarity clusterfarkle happening. Those will just clear on their own if there wasn't more significant damage done someplace.

Yea, there was definitely something else going on. All of the lights stayed on the whole ride home, along with locked steering wheel. It was a PITA to make turns

 

[IWMTom]

So I’ve checked the fuse links right now and cannot visually tell of any scorch or burn marks. It all looks normal.

I’ve checked the engine and dash fuses, and they are all still solid except the F19 fuse, which I’m going to go replace now.

However, the brand new battery I bought yesterday is completely dead after one night. The engine nor any electronics are turning on in the car.

I'd recommend scanning for codes, saving the log output, then clearing the codes and see what remains.

That'd give a good indication of whether you've fried anything which is an entirely plausible outcome of reverse polarity.

 

[staying_tuned]

Put your OEM battery back in and attempt to jump-start it assuming you have cables. If you do and its successful, take it to your local indy/VW dealership. If it won't jump, have it towed. I enjoy DIY as much as most but the potential for this to turn into bigger problem from attempting to resolve it yourself is significant enough to justify bringing it in even if it means on a flatbed.