I just recently had a P0720 code pop up in my 2006 dodge ram 2500 diesel…. Code says it’s an error with the out put shaft speed sensor…. Had symptoms of improper shifting and and rpm issues. I swapped the sensor and once I get the garbage out of the back of my truck I plan on taking it up to highway speed to see if I still have the same issues… one of my concerns however is that the sensor had some metal filings on the magnet and I’m not sure how much is too much? Anyone on here have this problem before? I should add that I cleared the code a couple times before swapping the sensor and was able to use the truck normally for the rest of the trip home as this happened on our way back from our camping trip. It seems to be an Intermittent issue.

 

The metal filings on the end of the sensor can interfere with how it reads.... simply cleaning it off *might* have fixed it.

I expect *some* metal filings, how much is excessive? Good question. Don't have a pic by any chance do ya?

 

They aren’t crazy bad chunks I don’t think but they are definitely there

 

Clean it off, put it back in. That's actually pretty normal.

 

i had already purchased a new sensor for the price I don’t want any future hassles so I just swapped it out

 

That works too.

 

When you said you "swapped" the speed sensor, did you replace it with a new one?

Both speed sensor's are identical on the 45RFE, 545RFE. A diagnostic step could be 'swapping' the input and output sensor and seeing if the fault (MIL code) followed to the other position.
If you didn't buy a new MOPAR brand sensor, I would hang onto the original and if the problem returns, troubleshoot as required. When I started riding motorcycles was when I learned that many times the best parts are factory parts, so I try to stay away from the discount imitation parts, especially the ones that have a 'lifetime guarantee"

What HeyYou said about simply cleaning the chips off of the magnetic sensor is true.

* Please remember to return and let us know how this all plays out.
I have been searching this forum (and ram forum) looking for similar information regarding my transmission pressure transducer and I find forum posts that just go dead. I presume that the member got his truck fixed, and had no more reason to return and tell what they did to fix it. I wish they would, I would likely have the answer I am looking for.

 

Oh, and when you put things together on a transmission, like inserting those sensors into the case... use Vasoline as an assembly lubricant (or transmission fluid)
Vaseline will dissolve in transmission fluid because it has similar molecular properties.