Central locking keeps locking itself - is my 4R haunted?

[StealthyBlagga]

Newbie here - I hope you guys can help me out.

My 2008 4Runner has factory-installed keyless entry and a cheap dealer-installed alarm (the type they put on it while it's sat in their lot - it has always been a bit dodgy). Years ago the central locking was re-programmed by the dealer to open all doors at once. The vehicle has 70K miles on it.

Recently, the central locking has started re-locking itself immediately after opening the vehicle with the keyless transmitter. I press the OPEN button and the vehicle unlocks OK, but then within less than a second it immediately re-locks. To get in the vehicle, I have to press the OPEN button and then immediately pull on the door handle. Even then, the other doors lock.

I have tried two different transmitters - both have the same problem.

Has anyone encountered this problem before? Any suggestions for troubleshooting?

 

[dadigab]

The factory alarm system can do this if it senses that door was not unlocked by a key or key fob (if programmed to do so). Try unlocking door with key and see if they re-lock. Download FSM and read thief deterrent section for more info on setting alarm to passive/ active with forced door lock control. I know you said you have aftermarket alarm but maybe you now have both? or it is controlled by door lock ECU.