Code P1623, Prom Error

WARNING: This page is about a different car, the 1995 Oldsmobile Ninety-Eight and 1995 Buick Park Avenue. However, it is still accessible from the selected car via links, so may be relevant.

Ensure PROM is correctly inserted in PCM socket. If okay, replace PROM, clear memory and recheck. If Code P1623 reappears, replace PCM.

NOTE: To prevent possible electrostatic discharge damage to PCM or PROM, DO NOT touch component leads. DO NOT remove integrated circuit from carrier.