Hmmmm weird, Sounds like it got confused when you took the shunt fuse
out. Try this. Open the driver's window and the bonnet and take the
key out of the ignition. Get out of the car and close and lock the
door. Leave it alone for 5 minutes (sleep mode). Now disconnect the
battery, both leads and hold the leads together for a further 5
minutes. Reconnect the battery and lean into the open window and
switch the lights on. This wakes the BSI up gently! Now open the door
on the plip and try to start it.
Economy mode will go if and when it starts.
If that doesn't work suspect the key has lost its settings and you
will need to take it to a Pug garage to recode the key. Have you got a
spare key? Does it work? You will need the code card that should have
come with the car when you bought it.