PROM - Programmable Read Only Memory: Service and Repair

1. Remove ECM as previously described.
2. Remove PROM access cover retaining screw, then the access cover.
3. Using PROM removal tool, grasp PROM carrier and gently rock side to side while applying upward force. Remove PROM and carrier from ECM.
4. Noting squared off symmetrical reference end of carrier, remove PROM from carrier.
5. Install new PROM into carrier, making sure molded half round depression on PROM is positioned at reference end of carrier. Also make sure that PROM is equally spaced around carrier.
6. Position carrier into PROM socket, making sure reference end of carrier is aligned with small notch in socket at pin 1.
7. While pressing down on carrier with fingers, press PROM into socket squarely using a suitable blunt instrument.
8. Install access cover and cover retaining screw.
9. Install ECM into vehicle and connect the numbered and lettered connectors.
10. Start engine, ground diagnostic test lead, and check for Code 51. If a Code 51 occurs, check for incorrect seating, bent pins or backwards installation of PROM. If the PROM is installed backwards it should be replaced, since turning on the ignition switch will immediately destroy an incorrectly installed PROM.