Having a problem with the t/c going into lockup too early.
Now keep in mind whenever I get in the truck, I turn the O/D off.
While driving along, even at around town speeds of 25-35 mph, the t/c goes into lockup.
This is really irritating when towing, has anyone put a switch in to prevent this?
Went to the trans shop, was told he can't reflash with his computer, have to go to dealer, he suggested the switch to prevent lockup.
Has anyone ever had this problem?
How did you fix it?

Rich

 

Sounds normal to me. When you leave the OD on when does it lock up?

 

Sometimes it will lock up at 20 mph. When towing, it lugs the engine down too much for my liking.
Not that the engine can't take it, it just seems to put too much stress on the trans. It does this no matter what position the OD button is in.

 

Yea, that's too low then. I'm not sure how to fix that. Someone else will be along to help.

 

I'm really looking for a wiring diagram to see which wire from the tps I can put a switch in, or from the trans harness.
I'll look around and see what I can find.

 

THIS is not exactly what you were asking for, but it does touch go over the adjusting of the the TPS in order to change the shift points. I do not know if this also adjusts the lock up point or not.

Rich.

 

TPS and the speed sensor are what controll the lockup if I recall correctly. My brothers 96 will lockup at 30 under light throttle settings.

When your lockups up at 20mph, what kind of throttle are you giving it? Puttering around at idle, 1/4, 1/2, WOT?

Could be your TPS if your getting erractic lockups.

 

You can tap the brake pedal with your left foot to unlock the TC if you're lugging the engine. A 3 position TC lockup switch would suit you to a T. There's a wiring that's been posted here. Try the search engine for lock-up switch.

 

I usually tap the brake pedal to unlock the t/c, just getting tired of doing it.
I'll do a search on the switch

 

I'd suspect the TPS first. Check it with a VM at the PCM. 3 connectors, far right, look for orange with blue tracer wire. Range .8 to 3.6V. Sounds like it is too low of voltage.

For the lockup wire, remove the transmission relay in the PDC under the hood, jumper across the contacts, not the power/ground, and on the PCM, center connector, look for orange wire, with black tracer on pin #11. There are 2 orange/black wires, just get the right one.

A ground to this wire will lock-up the TC, an open will unlock it.

Hope this helps.