01 dodge Dakota 4.7 45rfe tranny automatic SLT 4X4 crew cab 75K original miles
Carried truck to dealership no issues drain and fill tranny. 4 months later check engine light and limp mode. throws a 02 sensor and cranks shaft sensor and generic P0700 and went into limp mode. I replaced both and cleared codes. I drove short distance and throws P0320 cranks shaft sensor and P0725 Engine speed input circuit. Replaced the Crank shaft sensor with OEM and transmission speed input sensor and all codes cleared on their own. start driving all gears work short time later throws only the P0700 Transmission Control System – MalfunctionP0700. There is no other code being thrown.
If I manual shift all gears work when not in limp mode (no check engine light). while in limp mode (check engine light with P0700 code) I have no first gear. Fluid was 2 1/2 quarts low (THANKS DODGE). Reset code and drove again. This time I actually got about 45 miles on it before it threw the P0700 again. I replaced the ECM/PCM with a plug and play and it made no difference. doesn't seem to be slipping and makes no noise. drives great and shifts gears no problem until check engine comes on and code P0700.

I seen common problems with 42re 46re and 48re saying governor pressure solenoid and sensor (inside the transmission) My understanding is the 45RFE doesn't have one inside the tranny. There is a transmission governor pressure sensor on the outside of the tranny on the passenger side. I don't mind replacing other sensors if that may help looking for any ideas at this point or should I carry it back to the dealership and let them hook it up to the DRBIII to try and further diagnose the P0700 code?

Any suggestions?

 

I'd replace the sensors

Here are a few of mine off the valve body an that all too common spring that breaks a lot .
-not too difficult if your handy..Use OEM only.
Maybe try it an if it resets with the same code get dealer to retest.

Valve body pic may differ depending on transmission.
Good luck!