6yz1187 Transmission issues. Machine will not move in F or R any gear. Getting 430 psi from the pump to tranny. Zero psi on any modulation valve forward or reverse. No trans codes present. Nothing in trans screen or filters. My question is, where does the oil going to the modulation valves come from?
Attached a couple of documents explaining the power train hydraulic system and the priority valve operation.
Okay. Great! Now how to troubleshoot the priority valve?