Rear hatch opens w/o key fob

[PaulInCbus]

I own a 2016 Murano SL with powered rear hatch. The other day I noticed that I could press the rear hatch button under the license plate and open the hatchback door, even though the car is locked and I don’t have the key fob on me or near the car. I tried turning on and off the manual switch in the glovebox and using the key on driver’s side door to unlock/lock the car and the gate still opens automatically even though all the other doors are locked and the key fob is nowhere near the car. Any ideas on cause and solution? (My car doesn’t have an actuator)

[VStar650CL]

You're right that there's no actuator, the auto liftgates only have a cinch motor controlled by the ABD module. The "door lock" instruction is basically just a CANbus message from the BCM to the ABD, so there's nothing mechanical that "locks" the gate except for the ABD not responding to the button. I can only imagine two things causing that, either there's a lost fob inside the car or your ABD module is cuckoo. Try climbing in the car without a key and see if it will start. If so, it's time for you to play Raiders of the Lost Fob.

[PaulInCbus]

I tried starting the car but no go - car didn’t start, so no hidden fobs or golden idols lol. So might be ABD module?

[VStar650CL]

Well let me revise that. Looks like it has to be a cuckoo BCM, which is way worse. I just pulled the wiring diagram and there's not even a CAN lock command. Turns out the BCM monitors the "open" switch and not the ABD. It sends an "open" signal to the ABD on CAN if the car isn't in a lock state. Since it's locked and the ABD still opens the door, it means the BCM either forgot the car is locked or isn't looking at the lock condition, and is sending an open signal anyway. Either way, it looks like the BCM is the only possible culprit.

[VStar650CL]

Hmm, you know... one time I did see a case where electronics in a customer's house were actually spoofing RKE (fob) commands. Have you tried doing this with the car parked in different spots?

[PaulInCbus]

Thanks for looking into it, even though it wasn't the news I was hoping for. At least the car's paid off! And yes, I can replicate the problem anywhere the car is parked, so it can't be a spurious electronics signal. Thanks again !!!