Got a 46re not getting overdrive. Haven’t gone through everything yet but checked fuse and solenoid to governor under hood. Solenoid itself is good but want to be sure weather the governor solenoid in tranny is working or not.

my question is: by jumping 12 volts to the solenoid terminal (#5 aka 87) would it activate 4th gear at speed? I did this yesterday by switching the jump while driving and saw no change. Not sure if this would definitively mean governor is shot or other factors need to be.

 

If the 1-2-3 shifts work properly, then the governor stuff is doing its job. PCM controls O/D solenoid on the ground side of the circuit. Solenoid will always have power when the engine is running.

What year is your truck, and what engine?

 

2000 5.9 4x4
i May have read wrong, but I thought that solenoid mainly operated the overdrive unit by diverting line pressure to it and away from 1,2, and 3? Wires are tough to reach / see with front shaft in the way, but would it be advisable to manually ground the wire at the tranny while at speed then?

 

So long as you are moving over 40 mph or so, grounding the O/D solenoid *should* engage it. (assuming the trans is actually in 3rd gear.....)

Is the trans temp light on? Or the Overdrive Off light?

 

No. No codes either. Just won’t shift into 4th. If I turn the overdrive off (light comes on) there is no change in RPM either. At first I thought it was maybe the gear ratio the previous owner put in. It has slightly lower gears but that would just make the PCM think the truck was moving faster.

 

The hot ticket would be to plug in to the PCM, and see what IT thinks is going on. Is it even commanding O/D? Or is it getting some odd information, such that it doesn't think its a good idea.....

 

My thoughts exactly. But I guess I would need a fancy code reader for that. The bugger is that a code “should” pop up if the other elements (speed/tps) are there. Given the rest of the range is fine rules out a lot and no tps codes. Service manual says use a scanner rather than give volt or resistance values on anything. The PCM should be ordering this and if it doesn’t happen pop a code. I’m gonna try to ground the 3-4 shift solenoid wire when I get a chance to see what happens.

 

I've seen this particular problem before..... The PCM thinks everything is just fine, but, it still won't trigger O/D....... and doesn't set a code telling you why either. These are always fun to figure out.