1996 Ford Mustang Owner's Manual - Page 107

Theft Indicator The indicator provides system proveout and operating status. The system activates the indicator when the ignition switch is placed in the ON or START position. This indicator helps to determine possible fault conditions and/or normal operating proveout. The system will illuminate the indicator for two (2) seconds then go out to acknowledge normal operating conditions. If the indicator does not illuminate at key ON or flashes, have the system serviced. Spare Key Programming Procedure Two electronically coded keys were supplied with your vehicle, use one of these with the procedure below: u Using a coded key that you can start your engine with, turn the ignition from the ON to the OFF position. ignition and turn it to ON or START. The vehicle does not have to be started. u Within 15 seconds, insert a new key into the If the key has been coded, the theft indicator will illuminate for two seconds. The key can then be used to start the vehicle. Repeat until all chosen keys have been coded (max=16). If the key coding failed, the theft indicator will flash and the vehicle cannot be started. One of 3 causes are possible: u The new key was not inserted within 15 seconds or u All 16 key codes have been stored or u The key does not have an electronic code 109