To accurately diagnose the Computer Command Ride (CCR) system, the CCR Diagnostic System Check must be performed before proceeding with any other testing. This method does not require any disassembly. First, connect a jumper between DLC terminals 3 and 4. Then turn the ignition switch to the RUN position. This places the controller in a Blink Codes mode, and will cause any error codes stored in the controller to be displayed by the driver switch L.E.D.s. The Blink Codes sequence starts with a short lamp off period. Then, code 12 is displayed three times to mark the beginning of the sequence. Next, each stored error code is blinked out in ascending order. Each error code is displayed three times before proceeding to the next code. After all error codes have been displayed, the entire sequence will begin again by displaying code 12 three times. This will continue until the jumper between pins 3 and 4 of the DLC has been removed.