Hi im new but i have a problem and am sort of desperate : / My sis in law owns a 1994 dodge ram 2500 5.9L, Her engine light is on, and the code is the DTC 45 code which according to http://dodgeram.info/Engine-Gas/OBDI/pcm_fault_code.htm is "Transmission OD solenoid circuit failure. Open or short in the transmission overdrive solenoid circuit". But when hooked up to a scanner the code is DTC 45 but says Transmission fluid temperature sensor input above acceptable voltage. Same thing i believe. I'm wondering what parts to throw at it first? Ok, im going to explain this the best i can, When going down the road and when the truck trys to go into overdrive it starts to shake until i push the overdrive button on and will stop shaking, and then it gets to another point where it starts shaking again and i turn the OD off and then its ok.

 

Switch on the dash is O/D off when the light is on.

If you have a trans temp sensor on yours, it will be on the cooler line, right near the trans. have a look, and see if you even HAVE one....

Sounds like the O/D solenoid is dying......

If, with O/D off, as SOON as it shifts into fourth, you start feeling the horrendous vibration, what you may be feeling is an engine miss, and nothing to do with the trans at all. The symptoms you describe could very well point to a performance problem, instead of a trans problem. (I get the O/D code once in while too, but, my trans seems just fine.)

 

Yah, see im troubleshooting it from 150 miles away haha, so i will just have to either go to her or her come to me, so i can explain it better (driving it) because she has no car sense whatsoever. I will update when i check it out, thanks alot man!

 

One minor correction in my above post..... with O/D ON...... if you get the serious vibration when it shifts to fourth...... etc. With O/D off, it will never shift to fourth.

 

Tell her to disconnect the negative battery cable then turn on the headlights for a minute. Turn off the headlights and reconnect cable. If the problem comes back, I'm betting there is a tranny temp sensor. Or it has the infamous plenum problem.