i have searched and found a few threads of folks getting a p0720 code and truck revving and dying. Just wondering if anyone has resolved the issue and what the cause was. I have an 01 ex with v-10

 

I believe code P0720 is for the Output Speed Sensor Circuit Malfunction...not sure much more about it though...

Perhaps someone else will chime in soon.

Good luck,
Joe.

 

Joe is correct. The code is for output shaft speed sensor which is located on the transmission tailshaft housing, I believe. There seems to be some issues with that sensor as well as the speed sensor in the differential housing. What symptoms are you having? Is that the only code? Often the overdrive light will flash when that code appears. That's about as much as I can tell you without knowing more about your specific problem. Perhaps others can chime in with some more information.

Lou Manglass

 

when truck is started cold it runs fine but when put in reverse the o/d light flashes and engine will die, put in neutral or park and when engine is restarted it will spit and sputter and die unless it is revved up and held there for a couple minutes and then is fine. upon checking codes i get p1000 test not complete p0720 oss p0722 no oss signal. why I get a trans code for engine problem I dont know. just replaced the iac and it helped for a while. I am just stumped. Any help would be greatly appreciated.

 

I'm not sure of the relationship to your engine performance problem but I suspect there is one. Regardless, you are showing a hard fault in the Output Speed Sensor circuit that needs to be corrected. I would start by checking the wiring at the sensor to see if it has been disconnected or damaged in some way. Next I would replace that sensor.

P1000 indicates the readiness test has not been completed. Probably just the result of recently erasing a stored code. I don't think it's anything to worry about, at least not at this point.

Did you have a fault code for the IAC?

Lou Manglass

 

The P0720 code means that there is an electrical fault in the OSS electrical circuit. It could be a bad sensor or a wiring problem. It is unlikely, but possible, that it is a bad PCM. It happens, but it is rare.

 

Those unreliable V10's

 

just giving an update, I believe I have fixed my truck. I found it would only die and act up when sitting in gear, such as at a stoplight. Ordered a set of coils off ebay and installed them with new plugs. This made no difference. Hooked up my diagnostic scanner and found when it would start sputtering the speed the computer see's would start going haywire, but the speedo would not move. This could only mean the oss. Checked wiring harness and performed flow chart per ford manual. found oss ohmed out of specs. Replaced the oss tonight along with two new oxygen sensors, they looked old. Drove home and it acted fine. So far so good, I'm keeping my fingers crossed.

 

just giving anothe update. The ex stated acting up again. I finally gave up and took it to ford. Two days and $120 dollars later they found a bad ground wire . Cant believe I didnt find it, but noone's perfect i guess. Got to give miracle ford in Gallatin Tn some props. It acts like it should now. Now just have to find a five speed to go behind the twelve valve thats going in it this spring

 

just giving an update my ex started acting up again same as before. every once in a while it would stall out and finally got to where it would die every time I stopped with it in gear. Took it back to ford and they checked it out and said it was a bad pcm. Well i wasnt about to spend $600 on a pcm with a cummins waiting in the garage. I checked and checked and couldnt find the problem. Yesterday just got to thinking and ran a wire from the engine to the negative post on the battery. Drove to work today and it ran perfectly fine, no problems at all.just putting it out there so it might help someone else.

 

i am curious if anyone has a few things i could try for this. ive been scouring the internet for days now about this issue.
2005 f150 4.6 4r70e 230k
p0720
p0721
p2106
have full reverse
put in in gear and try and go and trans fault and brings these up

what ive tried to far
425 ohms tested with new oss
new alternator
cleaned throttle body

not sure if i am checking it right but off the pcm when i check the signal to the oss i get no ohms or voltage. i am also checking this to the neg side of the battery.
i am not that good with electric things and testing so i am thinking i am wrong on this one.
can someone chime in and say how i am supposed to be checking off the pcm

the truck does have high mileage and may need a trans, but i feel with the signal code coming up i want to check that 110% before replacing the trans. the truck is very well taken care of and clean. always very well maintained. my other vehicle 05 grand cherokee w/ 230k original trans and 5.7.

 

If you do replace the trans I can almost guarantee that you will have the same problems you have now.

The first ones to tackle are the P0720&1. If those are fixed the third code may go away. Since you have already replace the OSS it is most likely that you have a wiring issue between the PCM and the sensor.

Unplug the OSS from the wiring. Unplug the wiring from the PCM. While probing the BACK of the connectors (NEVER push a probe into the end of the connector that makes the connection. That spreads the pins and makes connection issues you didn't have before you started) check each wire from the PCM to the OSS connector for continuity, and for continuity to ground and continuity to a power source in the PCM harness. One of those two wires has a problem.

 

that is what I am trying to do. not sure that I was doing it right.


with the ign on and also tested with the truck running.
I didn't get anything at the plug. if I pull the plug on the pcm for the trans and check the pin for the signal to the oss I get nothing. so like the pcm isn't sending anything to the oss. does that sound right? I checked for ohms and voltage. note I have my neg lead to the neg side of the battery and positive side to the pin on the pcm. I believe # 4 or 14. something like that I have the diagram at home to tell me which pins it is for.

 

I had the same problem....code p0720, speedo jumping all over the place, OD light flashing, mileage showing dashes, stalling at a stop. I removed the Superlift Tru-speed calibrator and the problems have all corrected.

 

Hey so my f250 is a 2004 my code is p0720 witch is output shaft speed sensor when I give it gas it kinda wanna bog down or it wants to kinda lag but idling is perfect just sitting still if you can text me 7fourZero607Sixteen69