Well we were driving my GFs 93 dakota v6, and I started to notice that the tranny won't shift into overdrive. It will hold 3rd gear until its maxed. I've checked for codes, nothing that wasn't there before (code 12, 32, and 55). The OD off button still turns on and off, but doesn't affect anything. The VSS seems to be functioning properly still (replaced less than 2 yrs ago), and the tranny fluid is full, and not burnt or anything. We made sure it was properly in drive as well. What do you guys think my problem could be?

I should add that its an automatic transmission in case anyone's wondering

 

the only controls I know of are rpm/mph and engine temperature....and the relay attached to the switch....

 

My guess is the speed sensor or a fuse. The speedometer is run by cable so the sensor could fail and you won't know. Make sure the connectors all around are tight and clean.

 

well i remember all the symptoms from this truck from the first time the speed sensor went. the drl wouldnt work, and it would stall if you stopped to fast, along with not shifting into overdrive. the only symptom of that its showing is not shifting into overdrive, so it leads me elsewhere. All the wires under there are tight and clean. Im unfortunately thinking it might be something inside the tranny went, and its time for a new one? I'm buying a parts truck so maybe ill just throw the 46-RH outta the parts one into my GFs 93 v6. She will never blow that one! haha

 

think it is a solenoid in the tranny my 90 did same thing when it was under warranty in/out of the dealer in an hour. can get to it by removing the pan. i will look later to see if i still have the paper work in the truck for more exact info. found paper work (after 22 years) replaced Speedo Pickup, also replaced OD Buffer, hope this helps!

 

After running the truck in this condition, it developed a code. Code 45 is what comes up, and after looking in the FAQ, "Transmission OD solenoid circuit short or open condition detected." If someone knows exactly where this solenoid is, I will hopefully be able to buy a new one and install it. This is the main driver, so it needs to be up to par, especially with the amount of highway she does with it

Nevermind, found the manual in the FAQ. Will update and let you know how the fix goes!

P.S, just a thought, but I also got code 17, which is engine running cold for too long, and from what this manual is telling me, if the engine doesnt reach 65*F, the overdrive solenoid won't get energized. Now with that being said, and the motor apparently running too cold, do you think if I changed out the 180* thermostat thats in it for the stock 195*, could that possibly fix the tranny issue? Just a shot in the dark

 

Something to note about these OD trannies, you want to be careful about it getting stuck in OD, happened to my son's dakota shortly after he got it used, but luckily it had an extended warranty. The tranny had to be rebuilt.

 

i run a 160 degree thermostat and mine shifts fine.

 

Could it be that your thermostat is staying open causing the engine to stay cold for a little bit longer? I mean if this is a continuous problem while you are driving, even for 5 or 6 miles, then some kind of sensor is screwing you. Even with a thermostat staying wide open all the time, your engine WILL heat up to above 65*F and energize the OD solenoid. I would replace the OD solenoid. If that is bad it could possibly be causing the truck to throw those 2 codes..got to remember. One thing can throw out a million codes that have nothing to do with what you are replacing..

 

That last part is exactly what I mean't by maybe the thermostat is throwing it off. But in terms of the thermostat being stuck, its not. Warms up and cools down normally. However, since we changed the rad, it started running colder, but not enough to make much of a difference in anything.

The tranny isn't stuck in OD either, it shifts 1 - 2, 2 - 3, and thats it. OD doesn't even kick in. I just did the rear brake line a couple days ago, is it a possibility that maybe when I was pulling the old brake line out, that I caught that wire and broke it?