Went to the movies tonight. Came out and my 1999 F150 would not start. Got the "Theft" light on the dash. Engine turns over but no start. I have only the 2 original keys. I got a ride home then went back with my second key. Same story. Why would the SecuriLock system think that my keys are no longer valid? What could fail causing this scenario? Is there a simple way to get this all back working? I am puzzled. I do not have any remote starter or any bypass. This is all just like it was when I drove it off the showroom, well older and uglier but you know what I mean. Thanks for your help.
Rick

 

If you turn the key to the run position and wait, the theft light does not go out ?

The only other thing would be the PATS transceiver antenna in the steering wheel column. ( pending the theft light test above ).

Over the year I think I have seen 2 posts where the PATS receiver was the issue. This is basically the antenna that reads the keys.

 

You are correct Scully. Last night the "Theft" light did NOT go out after 3 seconds in the RUN position. This was true for either key. This morning I went to the truck prepared to trouble shoot fuses, etc and have it towed should I not get it running. The "Theft" light did go out after 3 seconds in the RUN position and it started right up with either key. This is very puzzling. Whatever it was corrected itself after 8 hours sitting there through the night. Now what ?
Rick

 

Unless it has the symptom again where you can work on it, you will just need to wait.

not much diagnoses can be done, when it is working correctly.

 

Scully
Thanks. I agree. I did hook up my Actron code reader. No codes found. Will just have to wait.
Rick