Please give your two cents... Code P0731 Could it be caused by a Speed Sensor?
My 05 Ford Ranger XLT 4.0 V6 Automatic has an issue.
I was on the highway and I went to pass a car and the truck did not accelerate.
Manual 1 works.
Manual 2 works.
Drive Engages... will creep forward if truck is over 3-3500 RPM only.
Reverse Engages... will creep in revese if truck is around 3,000 RPM.
Park- As usual.
OD OFF Light flashing.... AAMCO diagnosis: Need new transmission 1st gear totally gone. Clutch band must be shot. They never dropped the pan. Only ran computer scan. Code: P0731.
Now if there was no first gear left, wouldn't Manual 1 not work at all? I'm not sure, since i'm not too smart on transmissions.. please let me know!
P0731: Incorrect First Gear Ratio.
If you are in Manual 2 and downshit to Manual 1 there is Engine Braking occuring.
Oil Change, Tire installation. 255/70/16 to 265/70/16.
Issues with tires: vibration/shaking in truck. I believed it was tire balance issue it appeared at highway speed 55-70mph.
So lets go to it already right?
Here is my theory.... I was online looking up codes and transmission problems..
Could it be the Speed Sensor (Transmission)?
Why do I think this?
Transmission Speed Sensor talks to the rear differental sensor. Speedometer in truck works. The speedometer works off of the rear differental senor right?
So if the Transmission TCM is not getting the information of how fast the truck is going, it would mess up a shift and engage the truck in limp mode right? I'm thinking that is what I am stuck in.
I was going to quickly change the Transmission Speed Sensor tonight, but no parts store had one in stock. After installation I was going to leave the battery disconnected for 30 minutes to let the computer reset.
My thought process is that the TCM is not getting the actual speed. Now after I had the new tires put on (larger) I noticed to accelerate I would have to be near 3,000 RPM. Usually I accelerate with the BG Goodrich MT's in 255/70/16 at 2000-2500 RPM. I'm starting to wonder did the change in tire size trick the shifting in the truck? Or could this be a Speed Sensor?
Also, maybe it really is a tranny problem and it needs to be rebuilt.
Please guys, Let me know your thoughts I'm bringing it to another transmission shop tomorrow for diagnosis. They are a smaller place that does rebuilding on site, and they do transmission repairs too.
2005 Ford Ranger SuperCab XLT 4x4
4.0L V6. 4:10 Gears. BFGoodrich Mud Terrain T/A KM's, Torsion Bar Crank, Bilstein HD Shocks, Autolite Platnium 5143 Plugs, Autolite Professional Wires, Tonneau Cover, Bed Liner, Chrome painted rear differental cover... Thats it.