I'm not the kind of fella to get online to try and find help but I have been stumped... The sit on a five gallon bucket shaking your head in the shop kind of stumped. I have a 2005 ram 1500 4x4 with the 454rfe and 3:92 gears. A few weeks ago I was on my way to town and topped a hill. On the way back down when I let off the gas the truck jerked downshift and has been im limp mode since. I found the rear dif reluctor ring was missing teeth so I replaced the rear dif being that the original was shot and leaking from axle seal. While changing the rear diff I went ahead and put all new speed sensors. Input, output, and rear center. Cleared all codes and test drove the truck. Pulling out the drive way it hit 1st, 2nd then 3rd. At the stop sign it never downshift amd took off in 3rd. Full limp mode. I went home replaced the solenoid pack. Test drove again and still in limp mode. The only thing that hasn't been replaced is the pressure sensor and its special order. They say if they order it it'll take up to two weeks to get. I'm stumped everything I've seen looks good inside t4ansmission with the valve body dropped. The fluid was clean and the bottom of the pan had no metal at all on the magnet. It was truly surprising how clean it was. What could be causing it to be in limp mode. I'm stuck i e tried everything I could think of.

 

545RFE
Limp mode brings codes, I know you said you cleared them, but what did you actually get besides p0700?

 

I just ordered governor pressure sensor and transducer from etsy.com...was $56 and came in 4 days.

you should get the whole kit that includes wiring, 2-3 accumulator spring, the governor block, sensors.

 

The codes I got after initial failure were P1790, po720, p1684, po700, po720, 35 37 82 83, now that the solenoid pack, rear differential, and sensors have been replaced the only code that comes is po700, 82, and 83. With it throwing the pinion factor codes could it possibly be a faulty abs module or ticm?

 

Just so that this doesn't end up being a dead end thread where the answer is never disclosed. It wound up being a broken pin inside the output speed sensor plug. The plug tested fine with the volt meter, but while testing plugs for the third time I realized one of the two wire terminals on the harness plug was oddly loose and protruding past the other terminal. After a few moments of investigation I found that if I played with the terminal I lost power on my meter. Used the pin tool to take it apart. Found the pin to be broke. Replaced it with another pin, reassembled and bam all codes gone as well as the limp mode. Thank you guys for ypu input I really appreciate it fellas

 

Thanks for the update and posting your fix 😊