service engine light when shifting from park

Hello
I have an o2 cavalier ls. When I shift from park with my foot on the brake, I hear several rapid ticks in the dash and my service engine light comes on. What could this be?

thanks

The check engine light? Or is there a check engine light and a service light?

there are two lights in the dash on the 02 cavalier that indicate trouble. 1 is the check engine light that most obd ii testers will retrieve the codes for. and a service engine soon light. i have the same exact problem and am waiting on an answer. my car has no trouble codes set in the computer but still the service engine light comes on , with the ticking sound, when shifted into gear.