4WD Input
4WD SWITCHVehicles equipped with four wheel drive (4WD) have an input to the CAB, which tells whether or not the vehicle is 4WD. This input comes from the 4WD switch status which is sent to the CAB via PCI Bus. While in four-wheel drive, the front and rear axles will operate together. With this input, the CAB is able to modify its operation to allow for 4WD operation, Should a need for Antilock operation occur while in four-wheel drive, the CAB will extend the amount of allowable dump valve cycles.