My 1995 Ford Thunderbird went into limp mode the other day and when I got home I pulled a p1747 epc solenoid short circuit. I got my multimeter, set it to 20v, and checked the epc wires on the connector outside the thransmission. I Got 12v then unbolted the pan and checked the connector going directly into the epc solenoid, again read 12v. So since the connections to the solenoid were fine I changed the solenoid itself. When I got everything back together, disconnected the battery, and added a couple quarts of dex/Merc i started the engine. Immediately after i start it it goes right back into limp mode and the p1746 is still there. Is there anything I missed?
Good that you verified power
Now you need to consider the other side
I believe the pcm controls the ground side of that pressure control solenoid
You need to verify the wiring to/from the solenoid and pcm are good, then check if the solenoid is being grounded at the proper time . . . I’m guessing it isn’t
I’ve seen a few cases where the problem is the pcm itself . . . but you’ll need to do your homework and eliminate everything else, before going down that road
Should you need that pcm, I believe it’s plug and play . . . once you’ve established exactly which part number you need . . . meaning with any luck you won’t have to visit the dealer for programming
Word of advice . . . if you need a pcm, I’d go for a new or rebuilt one. Don’t assume a used pcm from ebay or a wrecking yard is better than yours