Itsrm

Hi All

I use a 2011 G37. The vehicle will crank and won't start except I disconnect the negative terminal and allow it sit for a while.

Lets say I go to get some groceries. By the time I come back to the vehicle, it won't start till I remove the negative terminal and give it some time.

The only way I can start it is if I remove the negative terminal on arrival at the grocery store and reconnect when I get back to the car.

I have been removing the terminal every night before I go to bed and reconnect in the morning so I can drive to work.

I have measured the voltage on the battery when it cranks and won't start and I get 12.65v. The vehicle has also been scanned with a U1000, B2193 and B260A codes .

I should also add that when it cranks like that and won't start, I can't use the stop/start button to turn off the car. If I press it, rather than turn off the car, every light on the dashboard goes away leaving a yellow key sign. A second or two later, the instrument panel lits up by itself and all the lights are back. This will go on till I disconnect the negative terminal.

What am I looking at please?

Itsrm

Thank you. I'll do that and revert

The previous owner had a remote starter installed. Any idea if this could this be responsible in anyway?

ILM-NC G37S

iTrader: (3)

This issue has nothing to do with a belt or exhaust blockage. It is a electronics issue, possibly a bad ground contact but unlikely.

That could be a very high possibility.

To add, check for water in/ near/ around the passenger-side footwell area. If any of the modules like the BCM or the ECM/ or wiring is wet/ damp this could cause your issues.

In your case: U1000= CAN Communication Error, B2193= BCM (IMMU)-ECM Chain, and B260A= Ignition Relay. In a nutshell, because the CANBUS signal is at fault (U1000) the BCM is not properly communicating with the ECU (B2193) which in turn is not turning on/off the ignition relay (B260A) which does not start/stop the engine. As the BCM is at the "top" of the chain, all of these point to the BCM having a fault.

If the BCM and everything under that dash is bone dry, and you still have the U1000 code with the yellow key icon on the dash, more than likely the BCM will need to be replaced. You can try researching what brand of remote start system was previously installed and see about disabling or removing it entirely to see if the car returns to "normal."

BULL

One possibility could be a steering lock failure after you've diagnosed other stuff.

When did it start?
Did you buy it like this?
Did the remote start ever worked?
How long have you been removing the terminal for?
Like​​​​​@ILM-NC G37S mentioned, your issue might lay in the remote start feature.

In most key fob cars, this feaure uses a bypass for the key fob and a receiver that interprets the lock commands as a signal to start.
Usually this is added and two options for starting are achieved, remote and physical. It is quite possible that if the system died or was removed that it's no longer sending the commands to the BCM and this is what youre going through. This would also mean that you bought the car like this.

Start with removing the bottom half of the dash on the driver's side and pay attention to non OEM wiring and where it ends, quite possible that the system was manually disabled and that when it keeps voltage for enough time that it enables lock/valet mode which is why you need to pull the power so the unit can reset, possible that if this unit is still connected and communicating that it's default mode upon voltage loss is to "start when commanded" however when it develops memory, etc it goes back into lock mode.

This behavior doesnt align with Nissan/Infinity behavior.

ILM-NC G37S

iTrader: (3)

Being that the U1000 & B2193 codes are triggered indicates to me that the issue is between the BCM and the ECU (via CAN). If it were the steering lock (ESCL) the B2014 code would have been triggered and OP would have a complete NO START condition. Not to say that it is not possible, but when following the iKey chain, the OP's symptoms occur after the BCM whereas the ESCL is before the BCM. That, and, as OP is not able to completely shut the car down (except via battery disconnect) points to the BCM.

My bet is either the remote starter kit is causing interference, or there is potential water damage.

Itsrm

So I've been quite busy and not had time until now to fix the vehicle.

Remote starter has been removed, BCM replaced and the issue remains the same.

While replacing the BCM, I noticed this device circled in the attached image. Can you please take a look and tell if it's a non oem device? Thanks for your support so far

@ILM-NC G37S @BULL

ILM-NC G37S

iTrader: (3)

The pink connector?

Pulling out the iPad...

Was it plugged into anything or just hanging there? Are you able to trace the wires or do they just disappear into the loom? Also, can you snap a pic of the terminal side of the connector?

Itsrm

Yes, the pink connector. The connector itself is not connected to anything and is just there dangling. It has six cables connected to it. Three black, two blue and one pink.

I'm yet to trace the cables but they are definitely connected to something at the other end.

ILM-NC G37S

iTrader: (3)

I think it is safe to say that the pink connector in question is NOT OEM. I can not find ANY 20-pin pink connector (no pink at all for that matter) on any of the FSM's or the numerous spare looms I have on hand. That, and the fact that Nissan does not allow connectors or wires to "dangle" as is in your picture. Everything is wrapped up in foam and tape. Despite their many faults, Nissan does not half-aȿȿ their wiring.

That said, I would try tracing those five (5) wires and see where they lead. Do they get "wire tapped" to other wires or do they disappear into the loom? What was the brand of the remote starter kit?

I will keep looking.

Itsrm

Thank you so much for your support. You were right all along. It was indeed the BCM. The previous BCM I bought surprisingly had the exact same issue.

I just replaced it with a new unit and the vehicle is perfectly fine now.