ABout 3 weeks ago my check engine light came on and the OD light came on too. I was getting some hesitation and rough idling. I took it to the dealer and they came up with a couple of engine codes and a few transmission codes. After getting a second opinion I replaced the plugs, plug wires, and passenger side O2 sensor. The truck runs better now but still shifts pretty rough between 1st and 2nd gears. I unplugged the negative battery terminal overnight to clear any codes and this morning while running errands the check engine light came back on (which I suspected would happen) so I took it over to Autozone so they could retrieve the codes for me. P0715 Input/Turbine Speed Sensor Circuit Malfunction is the only code that came up. Can anyone translate this for me. I have a 98 Explorer with 116k miles on it. I would appreciate any and all advice.
Thanks much.

 

It is my understanding that this is the input speed sensor on the transmission. You may be able to get a new sensor and replace it yourself... however, I've never done this and do not know how difficult the task is.

 

corroded teminals on the plug going to the tranny is a likely culprit

 

What plug are you talking about... the sensor itself?

 

And where would I look for it? Thanks.

 

if your trany is the same as the 99 expy,there is 2 pain in the butt sensors, right on top ofd the trany ,one in front the other one in the back of the trany,the one in front is the (tss)turbine speed sensor,on the back is the (oss)output speed sensor,lift your truck on ramps,is better that way becouse you realy have too move around under it, good luck

 

It might be on top of the transmission because I crawled under there and searched everywhere but could not find it. Where the Haines guide shows it to be there is only the dummy plug so Ford must have moved it just prior to the '98 year. CHilton says right of side of transmission about halfway down but no go there either.

 

what's you trany #?

 

Where do I find that?

 

Ok it's 5R55E.

 

Your fault is definitely a loss of signal from the sensor to the computer.
This is probably due to corroded contacts on the sensor or a broken/burned/shorted wire in the harness.
The only time I've seen these sensors on my '97 w/5r55e was when we dropped the transmission so I'm guessing they're on the top (I don't have the vehicle handy to check). Put your hand up there and you should be able to feel for the wiring harness, the INPUT sensor is the one at the front of the trans: Pull the plug first and check for corrosion then try spraying the **** out of it with WD40 and reassembling before you get further into it, unless you see something obvious.