oldschool350z

iTrader: (1)

Hi there,

So my z now just had this issue after my wife tried to open the passenger door as I used the key fob to unlock it. I think they cancelled each other out and perhaps shorted something out.

Immediately I was unable to open the passenger lock and did it manually by pressing it open.

The following now happens:
- Power windows will not function (window lock is not on and Window motors were replaced with OEM 2 years ago).
- Both power seats will not work (nothing happens in either button).
- Power locks will not work (either with fob or button inside). The key does turn the driver lock from the outside but that's all.
- Key fob works - locks the vehicle but the locks do not move.

I have checked all the fuses in the cabin and do not see any blown.

Any ideas?

karlt

You should get a copy of the Service Manual and see what circuits those systems have in common.

oldschool350z

iTrader: (1)

Thanks for the reply. I researched and found they have the BCM in common and a fusible link in the engine bay near the battery.

However, I don't see that it's burned out and not sure how to even get it out to replace. I searched but didn't see a DIY on it anywhere even for non 350z.

oldschool350z

iTrader: (1)

I left the battery unplugged over night and then everything's working great.

However, I just was on break at work and put the window down and opened the door and now the same problem. None of the power seats, windows or locks work..

update: I did the same thing unhooked battery and as soon as I open the door the settings revert to no power on those items.

zakmartin

BCM might be fried. I'd take it to a dealership and have them hook it up to a CONSULT to verify failure before shelling out the cash for a new one (unless you have a bi-directional car computer where you can remotely test the seats, windows and locks through the OBDII port.)

zakmartin

Because disconnecting the battery worked (for a short time anyway), you might want to re-focus on that. How old is the battery? How are the grounds from the battery to the chassis? Can you do a carbon pile load test or an internal resistance test on the battery to see how it's performing?

oldschool350z

iTrader: (1)

thanks for the reply. The battery is OEM and about 2 years old. I just put the car on a trickle charger.

any idea if autozone or advanced can run that load test? I only have a digital multi meter.

Up here Nissan charges like $150 just to hook you up to the consult machine. I know they are expensive but damn!

Im taking it to my mechanic to check out. My question, does the BCM control anything else? I might just learn to live with not using the seat, windows or locks. I could manually lock the driver side with the key I suppose.

zakmartin

Yeah, don't count on Autozone for anything. Honest. They'll tell you things that work are broken just to sell parts.

A dedicated battery tester isn't that expensive on Amazon. I recommend these if you're on a budget:




I have other equipment for the job, but own these and have found them to be reasonably simple to use and identify bad batteries with.

Since the battery is only a MAYBE as the source of the problem, the $150 you'll spend at the dealership to have them test the BCM through the CONSULT is going to be an easy pill to swallow if the alternative is spending 3 times that on parts or tools you don't need.

oldschool350z

iTrader: (1)

Thanks for the info I'll have to think of that tool will be used in the future lol.

i think I'm starting to pin point the issue. The power to those accessories stop when I sit down in the driver seat. I tried the passenger and there is no issue. I think there might be a short in the driver seat switch or wires underneath.

oldschool350z

iTrader: (1)

Okay I am 90% certain I located the issue. The wires under the seat were not secured and my seat was in the lowest position. I think the wires got pinched when I sat in the seat and created a fault or short.

I am going to zip tie them up so they are secure.