P0756; P0848; P0877; P0700 Help

[Tuf Toy]

My 2006 2500 Dmax Allison trans has been acting up . It has thrown the flowing codes:
P0756 Shift solenoid B check performance or stuck off
P0848 Trans Fluid Press Sensor / Switch B Circuit High
P0877 Trans fluid pressure Sensor / Switch D Circuit Low
P0700Trans Control Sys Malfunction

Any insight ? I have 43,000 miles on it.
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[DmaxMaverick]

When a bunch of codes show up out of the blue like this, it's usually something simple. I'd start with an external filter change and fluid service, and a thorough check of the electrical harness. Looks like a fluid restriction of some sort, or a loss of communication (poor connection or loss of ground).