2008 G35S Sedan (actually a 2009 production, but 2008 model year)

I think I've read every thread on the notorious leak (flooding) issue and every scatted thread about the BCM. My car flooded twice in the last month due to the terrible hose-firewall connector on the sunroof drain.

Maybe a week or two after the first flood, my intelligent key fob was no longer recognized by the car unless I had it inserted into the slot. The fob can still unlock/lock/trunk/alarm if I press the buttons, but the car does not sense its presence for push button ignition nor for keyless unlock via door handle buttons (truck won't open by clicking the button on the truck either, since the remote isn't sensed).

Not really understanding the issues with the flooding at that point, I replaced the battery in the remote.

Now that I have corrected the drainage issue and dried out my car, I am convinced that the water leak has messed up the BCM.

From what I gather, the BCM controls all the electronic accessories in the car. My windows, lights, turn signals, horn, etc all work. My seat controls work, but the saved pre-set positions do not (this stopped working before I noticed any water).

Because it's only the I-key sensing, I'm not 100% that the BCM is totally shot. Maybe it's a fuse or a loose connection?

Does anyone know any ways to confirm this hypothesis before I go through the trouble of replacing/reprogramming etc only to find that it's something else?

Thank you
K

 

Should find what you're looking for in this section of the factory service manual.

http://www.nicoclub.com/service-manual?fsm=G35/Sedan/2008/BCS

 

Yeah you will definitely have plenty of problems with remote entry etc if the BCM gets wet. If you check out the wiring diagrams you will see that the modules for detecting the key are wired through and to the BCM. You may also get a variety of other problems such as the car not realising the brake is depressed which will mean you can't start the car.

Long story short the BCM controls most of everything that's not the engine. If it gets wet weird things happen.

Side note, I have found a leak where the sunroof drain gies out the firewall and also some very small cracks at near the top of the windscreen where the a frame meets the windows both resulting in water getting in the cabin.

 

Klevez, was your leak on the passenger side? My wifes 08 G35X had the same issue where when she washed the car water would pool up in the sunroof area and leak down the front passenger pillar and run down to the glovebox/floor area. She is having weird electrical issues as well. The Slip/ABS/VDC lights randomly come on while shes driving but then upon restarting the car they turn off and don't come back for days to weeks at a time.