Code 53
WARNING: This page is about a different car, the 1994 Eagle Vision, 1994 Dodge Intrepid, and 1994 Chrysler Concorde. However, it is still accessible from the selected car via links, so may be relevant.
DRB displays INTERNAL CONTROLLER FAILURE or PCM FAILURE SPI COMMUNICATIONS. Condition is: Powertrain Control Module (PCM) detects internal failure.