05 Forester keyless entry/immobiliser fault

[PiersBMC]

Hi, I have a problem which is getting more frequent. When I arm the system using the key fob, the left hand indicator lights (front, rear and side wing) stay on.  Obviously if left this would run the Battery down.

Normally, when you arm the vehicle the indicators all flash three times and go out. When you open the car up to drive they should all flash once and the doors unlock.

Has anybody else had this problem and how did they solve it or what was the cause?   In normal driving the indicators Left, Right and Hazard works okay, so not the flasher relay.

I will start some diagnostics but any help will be much appreciated.   Cheers