Valve Body failure. Truck rear wheels lockup during failure as transmission was unable to get past 6 gear, sending truck into limp mode at highway speeds. Codes P0700 & P0747, no issues before failure. Dealership has replaced the Valve Body, but the part number model MQC part# 24065353 has not been redesigned and feel this will be a continuous issues to saftey not knowing when it will fail again.