SoCal Diesel CSP5 Switch with OBD Pass Thru Option for 2006 to 2018 5.9L Cummins & 6.7L Cummins!, to be used in conjunction with CSP5 Programming.  This switch is the same as the regular switch except allows you to "piggyback" other devices that rely on the OBDII port with it, such as electronic gauges, or for data logging.