Hi y'all. never had problems like this before.

67k miles. standard use, some rv towing. A few parking dings.


Yesterday the electrical system faulted. today it got worse. cross traffic, airbag, power running boards, blind spot, "key not detected" error, and more. The AC cut off, and the front windows wont go down (oddly the rear ones do, and the sunroof).


Its been dry for quite a few days, i don't think its a short due to moisture.


Based on a limited search of threads (i dont see a lot) possibilities include: Short somewhere (including a wiring harness), fuse, and the gateway (?) controller. The threads don't always follow up with root cause.


I have not yet tried disconnecting the battery for five minutes (why five by the way?) - will do tomorrow after work.


Anyone want to add some possibilities?


If its a short I may never find it without pulling the car apart. I'd like to rule things out first. The kid at the dealer said he'd never seen it before. But also, he sounded young lol.


Is it possible another issue is causing this like alternator or battery going bad?

 

Low voltage can do weird things but the alternator is monitored. So if there was an output issue it would have set a code as well as shown a Charging System message. The battery can easily be tested, however, the alternator supplies the load for the electronics while the engine is running. Additionally, the system has load shed strategies where it can turn off specific features if it detects the charging system is unable to meet the demands. Again, that would also show up as a message, if such occurred.

It's possible to be the gateway module, which is part of the diagnostic connector and bridges communications between the different networks in the system. It's best to use a scan tool to check for trouble codes and also see if any modules are currently offline. Everything else is based on guesses without concrete information (trouble codes, network module status, etc.,).

 

Sounds like water in the BLIS taillights shorting out the can bus. I would recommend unplugging the taillights and see if your issues go away.

 

This is a good point. Some of the functions noted in OP's post are on the MS-can. Depending on which network, due to the gateway module, some networks can take down other networks but not vice-versa. This one looks a bit more than just the MS-can, so the source may be in one of the other networks or gateway itself. A scan tool and looking over the trouble codes as well as current network status is pretty much required besides looking over some of the common known failure points - such as what you noted.

 

Good point, I forgot to mention a Forscan trouble codes may also help. Not a generic OBD reader, but Forscan.

 

Everything other than the "key not detected" message points to the MS-CAN bus and that really depends on what has caused that message. As said before, check the taillamps for water intrusion, and a DTC scan with FORScan or a diagnostic scan tool would be helpful.

 

Restraint (airbag) system uses HS2-can.

 

Do you still have the original battery? My 2016 did some really weird crap when the factory battery decided it was time to quit. Installing a new battery resolved all my issues.