MEM-CAL Unit

To allow one ECM to be used for many different cars, a device called a Memory-Calibration unit or MEM-CAL is used. The MEM-CAL is located inside the ECM, and has calibration information based on the vehicle's weight, engine, transmission, axle ratio, and several other factors. While one ECM part number can be used by many car lines, the MEM-CAL is very specific and must be used for the right car. It is very important to check the latest parts book and Serviceman Bulletin information for the correct part number when replacing the MEM-CAL. Parameter ED99 can be used to verify the proper PROM I.D.