Engine/Transmission (1994 - 1998) No O.D.

[Trashdawg]

I just picked up a 96 2wd auto. And the truck doesn't shift into overdrive. I have adjusted the tv cable. and checked the button, temp sensor. No codes. using the DRB the gov. pressure does not go above 30 psi when desired is 100 But I can see that the PCM is showing 4th grear on the DRB. but it doesn't shift out of 3rd lockup. Anybody have any clues.

 

[mechanic]

I would replace the governor pressure sensor, transducer and trans temp sensor. I replace all of them in one sweep. That is, if all the external connections are ok.

Good luck.

 

[B.G. Smith]

I just picked up a 96 2wd auto. And the truck doesn't shift into overdrive. I have adjusted the tv cable. and checked the button, temp sensor. No codes. using the DRB the gov. pressure does not go above 30 psi when desired is 100 But I can see that the PCM is showing 4th grear on the DRB. but it doesn't shift out of 3rd lockup. Anybody have any clues.

It sounds like your TQ is not locking rather than no OD, the TQ locks last, after shift into OD. Next time you drive the truck, when it is in what you describe as 3rd lockup, with foot steady on accelerator, touch the brake pedal just enough to activate the brake light switch, watch the tach, the rpm's should go up about 500 rpm if the TQ unlocks, if the rpm's don't change, you're in OD unlocked. bg

 

[DieselTim]

I am working on a 96 2wd also for the same problem. I have tapped into the brown (overdrive wire at the pcm) and the orange (lockup ) wire and found that the 12vdc drops out when the od is suppose to shift, I do get the 500rmp change but no OD. I am wondering if the coil could be shorted and still pass the 12v back to the PCM or does anyone know what the OHMs is suppose to be. I am going to try to do a pressure test asap ( soon as I can get on my lift, got to finish another round to it first), to see if I have the right pressure for the OD to engage. I want to check the coils before I pull the pan so I will know if I need to buy a coil pack, it would be nice to have onhand to save down time, if it is needed.



Thanks,



Dieseltim