Strange Truck Problem...

I drive my truck a lot.  It's a 2003 model and I have driven it nearly 220,000 miles.  It has been very reliable, until Thursday.  I had just finished teaching a scheduling class, went out to the truck, turned the key.  It turned over but would not start.  I managed to get a ride part way home and Mary Ann came to get me.

Now the debate was, "Do I take it to the Ford dealer or to my friend, Deron Shady?"  I called Deron to see if he wanted to attempt the job.  He indicated that he was very familiar with this engine and that he'd be glad to take it on.  Friday morning, the tow truck delivered the truck to Deron while I was at his shop.  As soon as the tow truck left, Deron said, "I've got a suspicion."  He got into the truck and started it.

It seems that Ford used a Passive Anti-Theft System (PATS) on my vehicle -- and a lot of others also.  Inside the head of the key is a tiny magnetically activated radio transmitter.  When the key is inserted into the lock, it passes through a magnetic field that causes the transmitter to send out a brief coded pulse.  The computer in the vehicle recognizes the pulse and activates the engine's ignition system.  On my truck, something had gone wrong with that sequence.  Deron had turned the key over or inserted it at a different rate or something, and it worked.  I left it for him to check out further.

In the meantime, I've ordered two replacement programmable keys.  His experience is that merely replacing the old keys often fixes the problem.  I sure hope it takes me another 220,000 miles.