Firebird V8-305 5.0L VIN E TBI (1989)
Alarm Module: Description and Operation
Passkey Module And Passkey Ignition Key - Matching Codes
The brain of the PASSkey(R) system is a special decoder module that reads the pellet resistance through the lock cylinder contacts. It then compares
this key code with its own internal code.
If the codes match, the decoder supplies a ground for the starter enable relay and modulates a 5 volt reference signal (at 2.5 volts) from the ECM or
PCM which will then pulse the fuel injectors.
If the codes do not match, the decoder module sets its internal timer which locks out starter operation and fuel enable for up to three minutes.