Nissan Sentra 2007 2.0
Gears slipping, bad gas mileage, erratic shifting, slow response
Solenoids malfunctioning - engine diagnostic error codes show solenoid failure, transmission fluid sensor error.
I am confident if you are showing the error codes below, you do not need a new transmission, but just some inspection of the valve body will probably reveal a disconnected wire. I harvested a used valve body for parts from a junk yard, but it turns out mine was fine, I just had a loose wire! Take your time through this process and anticipate 4-5 hours for removal / reinstallation if all goes well. If you know how to use a socket set and know what a disconnected wire looks like, YOU can do this!
-P0847 Transmission Fluid Pressure Sensor Switch B (&A)
-p0705 transmission range sensor A circuit
-P0752 Shift Solenoid A
REMOVE AND INSPECT TRANMISSION VALVE BODY:
1) Remove Drain bolt and drain transmission fluid
2) Remove all bolts surrounding transmission pan (size 10 metric socket)
3) Remove pan, exposing Transmission Valve Body (size 10 metric socket) (see picture) **Start by taking lots of pictures before removing anything so you don’t have to guess how it needs to be reassembled!
4) Remove wiring clips with small screwdriver to push tabs in, wiggle clips loose
5) Remove shift actuator arm bolt (size 14 metric socket)
6) Remove all bolts surrounding the Transmission Valve Body (size 10 metric socket), remove bolts around the transmission filter too, pull filter and set it inside the tranny pan for now. (Prepare for the Transmission Valve Body to fall out, so have A LOT of rags and hand pressing against valve body, so it doesn’t drop hard.
7) Once removed, **Start by taking lots of pictures before removing anything so you don’t have to guess how it needs to be reassembled**! Inspect the cylindrical (solenoids), there should be 4-7 of them (specifically look at the 4 in a row). Mine showed solenoid (number on top of solenoid) 0752 wiring was disconnected, causing a short. I used a allen key to remove the solenoid, then a small (tiny) screwdriver to pry the delicate black clip that holds the wiring to the solenoid in place. I then stripped the wiring exposing a tiny bit of copper, and pushed the wires back into the delicate clip, then with my hands snugged the clip back onto the solenoid terminals, and bolted the solenoid back onto the top of the valve body (where it came from).
REINSTALL TRANMISSION VALVE BODY:
8) I gently pushed Transmission Valve Body back up into place inside the transmission housing. Make sure to use a small screwdriver or thin rod to push the small arm (looks like a grey/black double sided fork gently in so the Transmission Valve Body, so it snugs in without force. This is responsible for your reverse. **NOTE**, for issues specific to reverse, like Reverse revving, and not engaging into reverse, BE SURE to make sure there is a black washer inside the transmission casing (see picture **small black washer on left of picture** - Probably fell out into your drain pan), this helps create the seal between the Transmission Valve Body, and the internal casing where the fluid is delivered, specifically for reverse gear. This washer if missing will not make reverse work!
9) Holding the Transmission Valve Body in place, put in the bolts around the housing, not too tight, just snug. Re-install the tranny filter as well, same size bolts.
10) Re-connect wiring harness (two clips), starting with the furthest clip (connect first), then to the larger clip (second).
11) Re-install the shift actuator (be sure a cylinder like piece of metal goes into the shift actuator rod first, then the rounded arm, then the lock washer, then the nut (size 14 metric).
12) Put gasket back around tranny pan, push tranny pan back on, and snug all bolts surrounding transmission pan (size 10 metric socket), just snug, or they will strip!
13) Replace Drain bolt
14) Pour transmission fluid back into dipstick reservoir
15) Start engine, parking brake engaged, walk the shifter through all gears about 5 times PRNDL, LDNRP, PRNDL, LDNRP, PRNDL, LDNRP, PRNDL, LDNRP, PRNDL, LDNRP.