Dodge Cummins trucks specifically, when using the MM3 platform for tuning, require the use of a CSP5 switch that connects through the trucks’ OBDII port. Unlike other vehicles that can get away with a standard rotary switch with MM3, the 06-20 Cummins needs an extra push to work properly. The beauty of this switch, is the OBDII connector has a flip side that allows you to still get power to other aftermarket accessories that require use of the vehicles’ OBDII port.
