S&T Series Blazer, Bravada, Envoy, Jimmy, Rainier, Trailblazer, Xtreme

Flash Eeprom


GM vehicles with OBD II systems (including 1991-95 Saturn models) use a flash erasable programmable read only memory device to make running changes.

In most cases, a computer is used to download the latest changes (listed by VIN code) into a PC or the Scan Tool. The service bay PC or Scan Tool is then connected to the vehicle so that it can verify the current PROM calibration to determine if the PROM needs updating.