Mercury Mystique anti-theft key?


I bought a used 2000 Mercury Mystique one week ago and the other day it simply stopped working. It was running and suddenly just stalled and wouldn’t start again.

After a ridiculous series of events, the car finally got towed to a service station and I’ve just heard fromthem that think the problem is with the anti-theft key.

Apparently the key I received with the car is not the original key, it is a copied key that doesn’t have the encoding for the alarm system.

Is this possibly the correct answer? Would I have been able to drive the car for an entire week before it stopped working?

Please help! I don’t want to pay $150 for a new factory-made key if it won’t solve the problem.


You would not have been able to drive the car for a week if this was the problem. The engine would have shut down within a couple seconds after you started it the first time. I suggest you get the car towed to somebody qualified to work on it, not a service station.


Does your car have a red LED on the dashboard? Does it flash slowly when the car is not running? Does it flash quickly when it does not start?


So, these guys are telling you that your car has an antitheft system that will allow a theif to drive around for a week before activating? I don’t think so! I’d be embarassed to suggest that as a cause.

Take it elsewhere.


The shop may be correct, maybe not. When the anti-theft system faults, it can cut fuel injectors action and spark action. A Ford/Mercury repair bulletin Article No. 99-26-6 can familiarize you with the anti-theft system.
The V6 engine (2.5L) has a timing chain which is good for the life of the engine.
The 4 cylinder engine has a timing belt, with an expected service life of 100,000 miles. The average mileage on your car is about 108,000 miles. The timing belt, if it’s the 4 cylinder, could have slipped.
The gods are smiling upon you, the site doesn’t list the 4 cylinder engine as being hurt if the timing belt slips. If it turns out to be the timing belt, on the 4 cylinder engine, make an offering of thanks to the gods (keep’em smiling)!