Car Codes

Im new to the forum. I learned of it form my freind who posts for his neon. he was telling me about how he checked his cars computer and change pre-set setting by turning his key so many times and flipping his lights on or off. i was wondering if this is possible with my 97 slt jimmy. Thanx for any help.

Silver Jimmy

All Settings bar fuel ratio are hardcoded. The only setting flipping the ignition on and off might change is the IAC valve position. Not much sense in that.