Ram44maR

Hello DTR -

Above, please see an old post in which the author described a "delayed shift" problem with his 47RE.

I too am experiencing a delayed 1st to 2nd shift ON INITIAL TAKE-OFF. That is, it only does this when you first start driving. Once that first shift occurs, the 47RE is fine for the rest of the trip--stop and go included. Having written that, however, I must include that the same problem will occur if the truck is parked temporarily [I'm not sure for how long].

The funny thing about this problem is how well the 47RE functions after that initial 1st to 2nd shift. Once that shift occurs, the tranny functions like the day I drove it off the lot.

As you can see, the author above also describes the OUTPUT SPEED SENSOR as the cause of his woes. Has anyone else out there found this to be the cause of this problem? If not, has anyone found another cause for this "delayed" 1st to 2nd shift syndrome?

In addition, I'd greatly appreciate an explanation of where the OUTPUT SPEED SENSOR is located, and any additional part number info or other helpful notes on how to replace it.

Have a great one...

Ram44maR

Any thoughts on this matter would be most welcome.

drecu

have you tried putting the trans in Neutral for about 30 secs before diving off & seen if the problem is still there? it could be that you fluid is draining back there is a anto drainback valve for the TC that sometimes goes bad & when this happenes it drains the fluid out of the TC & dodge transmissions do not cycle te trans fluid in park therefore you could find out if this is causing the problem but putting it in Neutral because it does cycle the fluid in N, so if your problem goes away that valve is bad & needs to be replaced or you could just put it in N for a few secs before you drive off everytime, I o this anyways just to get the fluid moving before I drive mine does not have a drainback problem though.


DRecu.

Ram44maR

Thanks for the suggestion, DRecu.

Yes, I've tried this and it seems to have liittle effect on the problem. I have noticed, however, that my RAM does delay going into reverse if it sits for long periods. Hmmm...perhaps you're on to something after all.

Thanks again

Cox83

I'm getting the p0720 code. On initial take off I get what seems like a dead petal. After first take off never does it again until the truck is turned off and restarted then on initial take off it does it again. I replaced the output speed sensor and cleared the code. The code came right back and the truck is still doing the same thing. Could I have gotten a bad sensor

AlpineRAM

Shamelessly stolen after using the search function on this site

SYMPTOM
P0720-LOW OUTPUT SPEED SENSOR - RPM ABOVE 15 MPH

WHEN MONITORED
Continuously with the ignition on, engine running, and gear selector NOT in park or neutral.

SET CONDITION
This DTC will set if the vehicle speed (reported from the CAB module) is above 24 Km/h (15 MPH) , and the monitored Output Shaft Speed is below 60 RPM for 2.6 seconds .

POSSIBLE CAUSES

• Park/neutral DTC present
• Intermittent wiring and connectors
• Output speed sensor ground circuit open
• Output speed sensor signal circuit open
• Output speed sensor ground circuit shorted to other circuits
• Output speed sensor signal circuit short to ground
• Output speed sensor signal circuit shorted to other circuits
• Output speed sensor ground circuit short to voltage
• Output speed sensor signal circuit short to voltage
• Output speed sensor
• ECM

Cox83

The sensor was good, I got under my truck and started looking at the wires. Some how the ground wire had gotten cut. I wired them back together and erased the code. Truck runs great, thanks for helping.