Engine Auto-diagnostics

[doctunneler]

I have a peugeot 406, 2ltr, 4 door N reg car and have had no problems with it untill today. The alarm sounded continuously, it would not start or accept the key code and the K Auto-diagnostics warning light is on and will not go off. I did the usual pulling and tugging wires under the hood and managed to stop the alarm but the K light is still on. I managed to drive the car home and it still starts but K light is still on.
The hand book tells me its the injection or ignition system fault and tells me to contact a Peugeot dealer, but the thought sends shivers through my wallet.
Has any Peugeot 406 owners had this problem? does any one know of a quick fix? could it be a fuse? can any one help or suggest a fix?
Any input would be appreciated
Thanks
doctunneler
UPDATE
Since yesterday the alarm is off. when switching on the ignition the K LIGHT COMES ON BUT GOES OUT WHEN STARTING THE ENGINE

[mjb]

That sounds like a rather worrying fault Is anywhere damp or wet in the cabin - footwells, ultrasonic alarm sensors, courtesy light?

Other than that I'd suggest getting it booked in at a dealer for a diagnostics reading to find out why the ECU's throwing up the engine management light - an immobiliser fault shouldn't throw that up!

Actually before doing that, check all your grounding points which with luck the Haynes manual should tell you about. Check nothing daft's happening in your ECU box too, like water ingress, split cables, etc