Possible bad BCM please help
 

Hello all I’m new to here and new to the G scene. I bought my new to me G last week and it had a couple problems I’ve been fixing but am stumped with this one and need some help. Car starts and runs fine does everything it should until I turn on the a/c. As soon as I hit the fan up arrow to turn on the air condition the trunk pops open and the flashers (4 ways) come on. If it were just the trunk that popped although a pain I would just get out and close it but I can’t drive down the road with my flashers on everytime I run my a/c. The guy I bought it from thought that the radio/ temp control settings cluster was bad so he gave me one he got used. Today I went out and took the old one out and put the other one in and sure enough same things happening. I’ve been reading in here and the only thing similiar the the problems I’m facing seem to be a bad bcm. I was just wondering if anyone has ever heard of this and can give me some advice. I read the diy on replacing bcm and there was a link on how to make sure it’s your bcm that is bad but when I clicked on it said cannot find link. Any and all help is much obliged.

The only real way to determine a faulty BCM is with the dealership diagnostic tool Consult-II / III. I would pay for a 1 hour diagnostic, it's about $125, tell them what's going on.

You will also need to pay a dealership 1 hour fee to mate the new BCM to the ECM. Plan on doing the BCM swap yourself in the parkinglot, talk to the service manager ahead of time and get it all arranged and they're usually cooperative.

Has anyone wired in a remote start or aftermarket alarm on this car? Could be a bad wiring job...

Could also be related to bad grounding for the module.

One more winter and and several modules would turn funky...
The blueish tint on the ring connector is not paint, its corroded copper.
https://cimg4.ibsrv.net/gimg/g35driv...28ff5a881b.jpg

Nope, that was my first thought as well.

Thanks for your input and great thought I actually just went out and checked and it was tight with no corrosion.

It was indeed the bcm I got a used one offline and took it to the dealership and she’s good as new. Thanks you all for your help