Engine/Transmission (1998.5 - 2002) Shift problems with 47re

[Speedo]

Haven't posted on here in a long time, recently trans developed a problem so here I am. If I put the lever in D the trans starts in 3rd gear and won't go to overdrive, doesn't matter what speed or throttle position. If I go from P, R, or N directly to low it will take off in 1st gear, upshift to 2nd when I move the lever up one notch, if I move the lever 2 notches it will shift from 1st to 3rd. I changed the gov pressure solenoid and the gov pressure sensor and nothing changed. Any ideas.

Gus

 

[cerberusiam]

What year of truck and does it have the range sensor for gear display on the dash?

 

[Speedo]

It's a 1999 and no range sensor.

Gus

 

[cerberusiam]

VB harness possibly, or PCM unless you got a bad transducer. A scanner to monitor demanded vs actual pressure would probably tell you something. A gauge on the gov circuit to monitor real pressure would also provide useful info.

 

[Speedo]

No transducer, mine uses a gov pressure sensor and I've changed that along with the gov press solenoid. I've got to wait till my wife's truck gets out of the garage. Its below zero outside, we're waiting for a set of injectors for her Dodge.

Gus

 

[cerberusiam]

The gov pressure sensor is the transducer, they are known to be less than reliable out of the box at times.

 

[jdooner]

Did you check for codes?

 

[Speedo]

No codes shown for the transmission.

Gus

 

[Speedo]

The gov pressure sensor is the transducer, they are known to be less than reliable out of the box at times.

Don't know if it makes much difference but the '96 thru '99 used a pressure sensor and in 2000 they started using a transducer, perhaps they were concerned about the reliability of the previous sensors.

Gus

 

[FCrowder]

Check the output shaft speed sensor. Can cause shift problems.

 

[cerberusiam]

Doesn't really matter which one, the quality is suspect at times. Could be sensors, could be the VB harness, could be something else. Need a scanner to look at demand pressure and actual to see if they match. Output shaft speed sensor may be the issue, not sure how they work on the older trucks. On the newer ones, a bad output shaft speed sensor just delays the 1-2 shift for 7 seconds then it defaults to standard algorithm. With a lack of OD something else is causing problems there.

 

[Speedo]

Thanks for the suggestions on what to look for. As soon as I get some injectors in the wife's truck mine will be back inside.

Gus

 

[Rhondasway]

I don't know if you got this figured out yet, but try replacing your trans temp sensor. Mine was freaking out and I replaced everything, checked everything (wiring, battery grounds, etc), and I kept having problems. Napa sells the part for roughly $25 and it only takes a few minutes to put in. You'll spill a little fluid (less than a quart?) so have some extra on hand.