Remote Central locking and alarm issue

[indieworks]

2001 3.2S Tiptronic. Been working on for a couple of years correcting faults - mainly electrical.

This is the status of my current fault-finding exercise.

Fault 1 My remote central locking is not working. The status led does not blink when operating the remote. I have to lock the passenger door using the dash lock button, then lock the drivers door using the ignition key. The courtesy lights don't come on when I enter or leave the car. I have changed the electrical part of the ignition switch to no avail and came to the conclusion that the car had slipped into the transit mode thereby removing the 12v supply from things like the boot/bonnet/interior lights. Took the car to a couple of indies to try to change to the handover mode without success due to lack of expertise, so abandoned the idea for a while however I continued with fault number 2.

 

Fault 2 Front bonnet release would not work from the release  switch or Durametric so suspect no alarm control unit output to the release solenoid. Found the manual release cable as a temporary solution, then wired a toggle switch to the acu output wire driving the solenoid directly with 12v routed from the cigarette lighter supply, which is always live. I then found that if I left the signal to the acu and release solenoid energised that the courtesy lights and remote key fob started to work as they should!!!!!!!!!!!

I then installed a 2 way centre off switch in the storage box, wired so that in position 1 I could just release the front bonnet, in the centre position everything was isolated and in position 2 a 12v supply was just fed to the alarm control unit output(disconnected from the solenoid wire). This is drawing 100mA so I am not too concerned about battery drain or component damage.

 

Now my courtesy lights etc. remote central locking and alarm are all functioning as they should. I have obviously lost a supply in the acu which I assume is due to the transit mode being selected but by accident have found a way round it. Cannot find a circuit diagram for the acu pcb to check the circuit design, but will not spend more trying to get out of the transit mode but will monitor the situation.