Common Problem #1: Solenoid & Sensor
“Generally when truck owners complain of the truck getting stuck in first gear in 47RE electronic controlled transmissions, there is an electrical problem in the valve body with the governor pressure solenoid,” says Terry.
The solenoid rapidly energizes and de-energizes to create governor pressure, while the transducer sends feedback to the powertrain control module (PCM) on governor fluid pressure and fluid temperature. When the transducer fails, it sends the wrong voltage to the PCM, and the solenoid will not be properly energized and will result in low governor pressure, in turn resulting in upshift failure. When the solenoid itself fails, it also produces the wrong fluid pressure; this can leave the truck stuck in third gear full-time (limp mode), will only allow second gear starts, and can delay shifts in cold weather or prevent upshifts altogether. Thankfully, though, replacement of the solenoid and sensor doesn’t require involved disassembly of the transmission.
A replacement solenoid that’s better designed for performance boosts is available from BorgWarner. With the pan off, pull off the lower part of the body (which contains the transducer) and then, using a small prying tool, pull off the clip holding the transducer. Insert the new transducer and reinsert the clip. Next, replace the solenoid, which simply pops out upon pushing it. Unplug it, plug the new one in, and move the new solenoid in place of the old one. When that is done, put the lower part of the body back on.