My father has a 2002 405, today he's had the battery disconnected for some or other reason (probably caravan related) he now realises this has caused a problem with the immobiliser, he gets a "red square with a key" light on the dash and the message "electronic anti-theft Device is defective"
I've searched around and found a couple of other people having had similar problem, but not definite solution, I got him to try the procedure suggested at
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no avail.
He has two sets of keys, one with plipper, one without (presumably the
2nd plipper has been lost over the years)I can't remember whether this car uses infrared or radio plipper, I know his last 405 was infrared, he seems to think his current car is a radio plipper.
Any suggestions to avoid taking it to a dealer?