I have a 2004 G35 Coupe which I have owned since new.

Over the past several years I have had a series of intermittent electrical problems that have caused various degrees of inconvenience.

- The passenger side window would only operate sporadically which seemed to be weather dependent
- The doors would not lock or unlock remotely
- The trunk release would not work from the key fob or the switch

I dont do my own work on the vehicle and the quoted cost to repair has always far exceeded the inconvenience caused, so I have let them be, enjoying when they worked and coping when they didnt.

As of yesterday morning the status was door locks not working, trunk release not working, windows both working. Then I left my car with a parking garage valet. When it was returned to me the drivers side window was open and it will not close. I have waited 24 hours hoping that a cool off in my garage may change this, but no luck. In Illinois a permanently open drivers side window is not an inconvenience -- it has to be fixed.

So to my questions:
Do the combination of issues suggest a faulty BCM or could these just as likely be wiring issues? Any other shared failure point I should be aware of?
Is there a way to get the window closed mechanically?
Is solving this likely to be something only the dealer will be able to address?

Thanks

 

I would start by checking the window motor itself, the door card is easy to remove, just three screws. Underneath is a flange of bolts holding the inner door metal panel to the door. Remove that flange, unplug the window motor. When you roll the window up or down the voltage on that harness should be either +12vdc or -12vdc.

If it's getting voltage then it's just the window motor that died. Replace and recalibrate the motor so your auto up/down works again.

If it's not getting voltage it could be a few different things.

Do all these problems correspond with going to the car wash or it raining? You might be getting water in the IPDM fuse box. This happens when the cowl drains get clogged up with debris.

 

I also have a 2004 that I purchased new. The window motors have been problematic over the years on all of these cars. If the window is stuck in the down position, bang on the inside of the door near the arm rest while pulling up on the window switch. At least it may allow you to close the window. I had to replace the driver's side lock actuator. It is a pain to replace because it is part of the door latch and has to be replaced as a unit. I am having issues with locking and unlocking the doors with the key fob. Sometimes it works and sometimes it doesn't. If I lock and unlock the doors manually using the button on the inside of the driver's door, the locks start working using the key fob. I am lost on that one, but since it's intermittent, I can live with it until it completely fails. As far as your trunk release not working, you may have a broken wire inside the rubber boot that connects the body wiring to the underside of the trunk lid. I kept losing the trunk light and traced it to the broken wire in that area. I hope you can solve these issues. It is frustrating and can get expensive if you do not do your own work. Good luck!

 

I have never seen the window motor fail intermittently. They usually fail as Cleric has said.

The door and trunk latches do get tired over the years, and failures are often temperature related as you noted.

A good thump on the outside door will often open them.
Also Don't be afraid to clean the latch with electric cleaner, or silicone spray, or any degreaser that won't eat paint and attract dust. (Thanks Cleric).

If you are having trouble opening the door from the inside, I would fix that as thumping the inside door card-skin will make more damage to the card-skin after a time. This failure can be a stretched cable or broken inner door handle.

Aside: most door card plastic can be mended with fiberglass.

 

Just an anecdotal data point: my driver's door window motor failed intermittently. Thought it was the switch at first because of that.