Hi everyone

So I drove to B & Q yesterday in my X300 3.2 and upon exiting the store, to my dismay, the whole central locking/alarm/immobiliser combo had stopped working. I tried it on the fob first, then manually using the key which solely opened the drivers door alone. The unlock button on the centre console doesn't work either. Upon putting the key in the ignition the Check Engine light goes out before I try to crank which I believe means the vehicle is still immobilised and turning the key yields zero cranks. The battery is good and chucking out 12.45v
Just had the RAC out and their engineer put a booster pack on to be doubly sure. All fuses are good so that's not the issue. Rac guy said error code P1621 is coming up. Anyone got any ideas as to what might have failed to cause this?

 

A lot of rain recently ?

See page 131

http://www.jagrepair.com/images/Training%20Guides/801S%20-%202000.pdf

I think the code is a phantom code seen before by others

 

Thank you very much. Can't see a fault description on page 131 that pertains to my issue though?