PROM - Programmable Read Only Memory: Service Precautions

A PROM is a sensitive electronic part and must be handled with care. If the connector terminals (pins) on the bottom of the PROM are exposed, avoid touching them. Pins can be broken easily, and the PROM can be damaged by static electric discharge. Follow these guidelines when replacing a PROM:

^ Disconnect the battery ground cable before removing a PROM. Reconnect the cable after the new PROM is installed.

^ DO NOT try to remove a PROM from its plastic PROM carrier.

^ Note the direction in which the original PROM and its carrier were installed in the ECM, and install the replacement PROM in the same direction. Most PROM's are marked with a notch at one end for orientation. Many PROM's can be installed in a reversed direction, which will destroy the PROM when power is applied.

CAUTION: A PROM can be damaged by static electric discharge. Avoid damage as follows:


^ DO NOT remove a PROM from its packing material until you are ready to install it. DO NOT hold a PROM by its pins.

^ Before entering a vehicle to remove or replace a PROM, touch an exposed metal part of the vehicle to discharge any static charge from your body or use anti-static wrist straps.

^ Avoid sliding across upholstery or carpeting when removing or installing a PROM. If this is not possible, touch an exposed metal part of the vehicle with your free hand before removing a PROM or installing a new one in its socket in the ECM.

^ When available, use an antistatic grounding strap attached to your wrist and clipped to a metal part of the vehicle body to prevent static charges from accumulating. Antistatic, conductive floormats are also available.

^ For some vehicles, it may be desirable to remove the ECM when replacing the PROM.

^ NOTE: See POWERTRAIN MANAGEMENT / SERVICE PRECAUTIONS / VEHICLE DAMAGE WARNINGS / ELECTRICAL PRECAUTIONS