I have a 2011 Infiniti G37x Sedan with 174,000 miles that I bought last month. I believe I have a faulty Body Control Module (BCM). My main window control panel will operate both of the front windows properly, but the rear left button on the main panel rolls down the rear right window. The rear right button on the main panel is not functional for any window. The window button on the rear right door operates that window properly, but the button on the rear left door does nothing.

I reset the BCM by unhooking the battery cables and waiting, then I put them back on. At this point the only thing that changed was that the rear left window would roll up with the main window control panel rear right switch. If i were to roll the window down with the same switch, the window would go down then the switch and window would become inoperable. I unplugged that window motor for now. Additionally, if I were to install a battery into the key fob, none of the buttons do anything other than open the trunk. The outside door buttons to unlock the car do not work, neither does the trunk button. I must enter the key fob into the fob slot to start the car as opposed to being able to just keep the key in my pocket. Besides those issues previously listed, all other interior components operate properly, and the car runs and drives fine.

I believe the issue is a faulty BCM, but if anyone has any other ideas as to what the issue may be, that would be greatly appreciated.

Say the issue was in fact a bad BCM, and i were to order the same model from ebay or take one from a parts car. Would it be possible to 'plug-and-play' the 'new' BCM, or would i have to take the car to an Infiniti/Nissan dealership for a reprogram.

 

Sounds like the BCM may have gotten wet. At that age and mileage it stands to reason the sunroof drains have failed. Any evidence of water intrusion into the cabin?

You can easily get a used BCM off eBay, that part is "plug-and-play," however, you will need to find a QUALIFIED/ LICENSED locksmith to program your key fobs to the replacement BCM.

 

Thank you for your response. I have not seen any evidence of water intrusion so far. I will look further into the sunroof drains, in the case I have overlooked any damage or wear.

 

Update:
I tested all of the fuses related to the IKey system and BCM, continuity seems fine. There is no evidence of water intrusion, but to prevent future issues I went ahead and rerouted the drain tubes for the sunroof to the A/C drain. Also, I used an air duster to clean out the BCM harness connectors. I tested for any diagnostic codes related to the BCM (see below). I then cleared the codes yesterday. All issues stated above are still present. Today I ran diagnostics, and none of the codes are back yet. With all the evidence I have gathered I am fairly certain the BCM is the issue. Although, I would like a second opinion, in case someone can steer me in the right direction.

There was also one code, not shown below, for the IPDM. Which I erased and has not come back.

 

The thing is, I believe that main window switch in your driver's arm rest also has its own internal processing. It's one of our black boxes and it can fail and cause odd window issues.

Here's the FSM for your power windows:
https://www.nicoclub.com/service-man...2011%2FPWC.pdf
(scroll down below the viewing window and "click here to download a copy")

And here's your BCM book:
https://www.nicoclub.com/service-man...2011%2FBCS.pdf

I haven't read up on this but if you dig into those books they might give you some ideas.

 

Another update:
The issue was not the BCM. I was able to go to a local locksmith and get a new key fob programmed. All IKey functions now work properly.
I did a little troubleshooting with the windows. I noticed that if unplug the Master Switch Panel, then plug it back in, all windows work properly for a short time. Then the windows go back to the same issues. I ordered a new switch panel from EBAY. Hopefully this resolves all the window issues finally.

 

That's good news. Let us know how it works out.

 

Final Update (hopefully): I just acquired a replacement Main Window Switch Panel. After installation the Rear Left window started rolling up and down properly. However, the buttons to the rear window functions were still swapped on the Main Panel. After a long while of online troubleshooting (manuals, forums, google, youtube, etc.), I noticed that the rear switch circuits consolidate down to one circuit before connecting to the Main Panel. That being said, I had the idea to swap the rear switches on the doors themselves, with each other. Lo and behold, problem solved. No more window issues.

 

Wow, well done. I did not realize the individual rear switches were also "encoded". Great find.

 

Because each switch is connected via serial link, the only way the Master Window Switch- and by extension, the BCM- "knows" each window "location" is via the encoding within each switch. So, yes, each switch is location specific.

For the sedans this is:
MW- Master Window,
RF- Right/ Passenger Front,
LR- Left Rear, and
RR- Right Rear.