Oldsmobile/Buick Repair: My car Service engine soon light is on, car experts, inbedded

Question
My car is Buick, lesabra-limited (1992) there is a light is always on recently. It gives "Service engine soon"massage. I went a garage to have it checked. A garage guy scaned the engine. the scanner gave a information of 'Code 58: vehicle antitheet system problem'. The garage guy spent much time, but didn't find the problem.

I ask car experts to give me some clues about this problem. What are the possiablities of code 58 prolem?

Thanks  

Answer
Hello Ming,
You didn't say what engine you had, so I checked several vin number possibilities, and each one that had a code 58 mentioned the fuel enable security system, or the pass-key system, which is an antitheft system that uses a little chip, or resistor inbedded in the ignition key, to send a signal to the engin fuel control system, that you are using the correct key, meaning there is a good possibility the car is not being stolen.
It is possible your ignition key is getting worn, especially in the area where the little electronic chip is, or the ignition switch tumbler in the steering column where that little resistor makes contact, is getting worn.
I would first try the other key, and see if that makes a difference.

The keys are pretty specific for that system, and need to be replaced from a dealer, or a locksmith familiar with the system.
The purpose is to keep someone from trying a bunch of similar keys, maybe finding one that will turn the lock, or just forcing the lock to turn, and starting the engine and driving away. If the correct key is not used, it will shut off the fuel system.

I would probably erase the code, and then see if it comes back.

Van