Yes you need a key paired to the ECU, (Assuming it's Zetec EEC ECU) there is a red PATS LED (If you have it) this should extinguish once the ignition is switched on which in your case it won't as it won't have received the code to disarm.

You can get a key programmed by Ford from the S/N IIRC, this can then be stowed behind the dash etc, so long as near the receiver, this would be a cheaper option than aftermarket management.

If it's a road car which I am guessing it's not it would void your insurance without a immobilizer as the standard car would have done, unless otherwise informed!

You can still have a push start in any case.


Martin