Recently O/D in my truck went out. Nothing noticeable happened at all. Just one day I tried to use it while getting on the freeway and nothing happened. The engine didnt downshift and the light did not come on on the shifter. Im just wondering what would cause this. I dont use O/D too much but its nice to have that extra boost when needed. Any help?

 

O/D is automatic (4th gear). The button on the shifter is to CANCEL O/D, not engage it.

Either the switch is bad, the wiring is damaged where it exits the shifter tube, there is an open circuit in the wiring harness, or the PCM is faulty.

 

You pushed the button and nothing happened? Otherwise, if you have no o/d anyways, your o/d band is shot, do a tranny overhaul at the same time! My o/d light went on/off even when my band blew, I just use to keep it off. You're switch may be kaput as mentioned ^.

 

yah I know the switch is to disengage O/D, I just always slip up and say that. I hope its just the switch that is bad.

yep pushed the button so it can downshift to 3rd and nothing happened at all. The tranny that is in there was taken from an Auto dismantler and came out of an 02. We bought the tranny early this year.

 

OK, sounds like the switch only, easyish fix. When the o/d goes, the truck literally goes into neutral, pushing the button gets it back into a gear.

 

whew. Thats a relief. So what needs to be replaced?