My truck had been taking an extra 2 or 3 seconds to shift from first to second gear just after starting (always OK after the 1st time through).

I finally got out my OBDII scanner thinking that I may be lucky enough to have a code show up.

Code is P0720 OUTPUT SPEED SENSOR CIRCUIT MALFUNCTION.

Does anybody have any idea what this is????

I was thinking it may be some coil (transducer) in the tranny, but I also read somewhere that there is a speed sensor at the differential (rear end) or something like that.

Anybody got any ideas???? I would appreciate it.

I'm guessing if I go to dodge and say "I would like a new output speed sensor circiut please" they will look at me like I'm stupid and ask me what that is.

So I'm trying to figure out beforehand what that is and how to replace it.

OK,

 

Believe me....they'll know what it is. I'm sure it's in a bin fairly close to the counter.

 

I just had this done today! My truck was getting stuck in first gear, and I had noticed it delaying shifting up prior to this. Since my rebuilt tranny was still under warranty, I took it in hoping it would be covered.

Though the check engine light wasn't on before I took it in, the shop said it came in and they pulled two codes, one referring to the tranny. It was the speed sensor. It is simply a part that screws into the tranny; they showed it to me and it looked like something you could do yourself if you knew what you needed! It was a $35 part, I believe.

The other code was 1693, and they said we needed to take it to the dealer for that. Funny, the CEL was still on when I drove it home, and the chimes didn't go off during start-up. At home I shut it down, started up again and the CEL was off! Yeah! Second code must have been triggered by the tranny problem, went away when the problem was fixed. Anyone know about that code?

 

I just had this done today! My truck was getting stuck in first gear, and I had noticed it delaying shifting up prior to this. Since my rebuilt tranny was still under warranty, I took it in hoping it would be covered.

Though the check engine light wasn't on before I took it in, the shop said it came in and they pulled two codes, one referring to the tranny. It was the speed sensor. It is simply a part that screws into the tranny; they showed it to me and it looked like something you could do yourself if you knew what you needed! It was a $35 part, I believe.

The other code was 1693 which referred to the ECM, and they said we needed to take it to the dealer for that. Funny, the CEL was still on when I drove it home, and the chimes didn't go off during start-up. At home I shut it down, started up again and the CEL was off! Yeah! Second code must have been triggered by the tranny problem, went away when the problem was fixed. Anyone know about that code?

 

Mine was doing the same thing except it was hanging in 2nd until about 1900 RPM. I suspect yours is hanging in 2nd instead of 1st. My speed was between 25 and 30 MPH when it would finally shift out of 2nd. It would do it only once after starting then it was normal until I would turn it off.

I fixed it by changing the "outout shaft speed sensor" which is on the tailstock of the transmission, upper right side. Cost about $25.00 and problem solved. Mine was setting a P0720 code.

Daniel

 

My code was indeed the P0720 also.
I replaced the same sensor you did for 23.99 at Autozone.
Problem solved.

Mine was basically needing about 4 seconds at 1600 rpm or above to go into second gear the first time around after starting. Then it was normal until I turned it off again.

Thanx for your help.

I took my scanner to it to make sure the code was gone, and It appears it's gone for good.

Thanx again.