P38A Alarm not setting…

Hi guys, backend last week, locked the car and the indicators did not flash as they normally do, so waited for the superlock to activate to confirm it’s fully locked, and left it till today, now I have checked and double checked and nothing.

The car both standard and superlocks, the indicators do not flash.

The alarm does not seem to set, have locked a willing helper in the car, superlocked it waited for superlock to activate and then the helper moved around the car, the alarm did not activate; Volumetric sensors do (should) activate in this state, therefore the alarm should have sounded.

Have locked it with windows down, and tried to break in, easy with window down the alarm does not activate. In this state I know the volumetric sensors do not set, so it was a case of opening the bonnet to force the alarm.

Question is there a separate fuse that feeds the alarm; nothing noted in the handbook (unless I have missed it), if yes where is it please? I suspect a fuse as it all worked fine and just stopped, just like a fuse blown.

If not a fuse any ideas as to what has caused this please?

Volumetric sensors have been known to fail on the P38....but this is usually accompanied with the Mis-lock horn blasts, unless this has been deactivated in the BeCM!

where are you ?? and what vechicle ??? year -engine etc ??? it does help !!!!!!

Alarm control is part of the BECM, it may have lost it's settings, not unknown. Needs checking with diagnostics.

Hi,

She is a P38A MY2000 V8 4.6 (Grantham)

Sounds like the BeCM then Datatek, I have been having issues with that as you may note from a previous article, where I fixed it a month or so ago with a rubber hammer cos the rear wiper would not work, I will run it into Ian Marshall and ask him to stick his diagnostic box on it for me.

Many thanks

v8twins said:

Hi,

She is a P38A MY2000 V8 4.6 (Grantham)

Sounds like the BeCM then Datatek, I have been having issues with that as you may note from a previous article, where I fixed it a month or so ago with a rubber hammer cos the rear wiper would not work, I will run it into Ian Marshall and ask him to stick his diagnostic box on it for me.

Many thanks

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Wet carpet in the drivers foot well? cheap option would be to check all the connectors on the BECM for corrosion.

Hiya,

No, no wet carpet, when i had the rear wiper issue I cleaned and sprayed the contacts and connectors so there should not be corrosion, but worth a double check thank you.