Hi All,

My car's electrical system seems to be a bit out of whack. I wanted to see if anyone has experienced similar issues or has any advice for trying to figure out what the problem is.

Sequence of events:

• May 19: The car started fine in the morning but couldn't even manage to unlock itself in the afternoon. My (four month old) battery was dead so I replaced it under warranty and went home from work.
• May 20: Car started in the morning with the "Service Engine Soon" light on; codes P0463 and P2103 were stored. Later that afternoon, the car would not start. After several phone calls to my mechanic and a couple of local dealers, I cleared the codes on their advice. The car then started right up and everything seemed fine.
• June 10: Car did not start on the first try in the morning. It started normally on the second try with codes U1000 and P2103 so I drove to work. Around noon, a coworker sent me a text message saying that my car's parking lights were flashing. I went to the car and the start button would not respond to being pressed. I pulled codes U1000 and P0463 (the P2103 code from earlier in the day was magically gone). I momentarily disconnected the battery and the start button started working normally again and the lights stopped flashing. I left the car with the battery disconnected so the battery wouldn't get drained.

Code P0463: Fuel Level Sensor Circuit High Input
Code P2103: Throttle Control Motor Relay Circuit Short
Code U1000: Controller Area Network Communication Line - Signal Malfunction

Battery generally somewhere between 13.4 and 14.2 volts.

I'm assuming all of that means that there's a short somewhere. Any suggestions for figuring out where? I'm pretty handy with small DIY electronics but the sheer scale of a car's electrical system baffles me. I rather check here before I start poking around with a multimeter. Any and all advice is appreciated!

I forgot to add this image to my original post. I can't find the edit button so I'm adding it in a new post...



That was displayed on the screen in the speedo today (June 10) when the start button was unresponsive. The steering was also locked; couldn't budge the wheel. Thankfully the car started normally after reconnecting the battery and got me home safely.

So the car has been at my local Nissan dealer since I posted this. They still haven't been able to pinpoint the cause of the issues but are arriving at the conclusion that the BCM is shot. As such, they ordered a new BCM to experiment with; they are going to install it in the car to see if the issues stop or continue. The new BCM should arrive today (June 18) so I'm hoping this fixes it.

Here's some of the fun stuff it has been doing...

Keep us updated bud. Interested in knowing what's causing this

Car is fixed; I picked it up Saturday, June 20 and, thankfully, it's been fine ever since. The BCM (Body Control Module) was replaced. The original BCM wasn't communicating correctly with the other modules and couldn't be re-programmed either. It was also failing to go into it's "sleep" mode and causing an amperage draw on the battery which would arm the steering lock.

The gauge cluster needs to be removed to gain access to the BCM. That whole process resulted in some damage to my dashboard in the surrounding area (there are several gouges and a crack). My dash has also been melting like many others. I've reached out to Nissan Consumer Affairs about it before but they were unwilling to help. Now in combination with the damage resulting from the BCM replacement, though, the service director at the dealership managed to secure a new dashboard for me and will be contributing the labor for replacement too. The new dash should be delivered a few days from now so there is certainly a bit of a silver lining to all of this.