Ok so I have all 4 gears and the trans is shifting smoothly. Now that it’s rolling smooth and aligned I got out and was cruising at 70 down the interstate and noticed the torque converter is not locking up. Where do I need to start with diagnosis on this one.

I have a code for the transfer case but I am not seeing anything for the transmission when I pull codes.




I’ll pull codes again when I get to the shop to see if I missed something or we have a new one.

 

And presumably the engine and transmission are fully warmed up? I don’t think it locks until fully warm. Maybe it’s not sensing it’s target temp?

 

Yup fully warmed up temp sensor reporting around 188-190 cruising down the highway on the live data

 

I am seeing a transfer case fault of

TRANSFER BOX LINK - SIGNAL LINE PERMANENTLY AT 12V OR OPEN CIRCUIT (DRIVING CYCLE A)

I cannot get the launch tool to connect to the trans ECM if it actually has one. It always comes up with a communications fault

 

It definitely has one. IIRC under the drivers seat. Maybe try unplugging it and spraying the connectors with electro cleaner?

 

Awesome will check under there tomorrow.

 

Finally got under there and the connector was clean and fully seated unfortunately. I ordered a good used one will give it a shot.

 

Hopefully that works. Did you try it after disconnecting and reconnecting?

 

Absolutely did however it didn’t make any change

Was contemplating resetting adaptive values to see what happened out of curiosity

 

So new to me module showed up, it does shift better but still no torque converter lock up. I did try switching to sport mode and noticed the truck wouldn’t down shift and basically drove like crap with either ecu. I wonder if that switch has an issue that’s causing a problem?

None of my code readers can do the trans adaptive value reset on it. I’m not 100% positive that is a thing with the 1997 model year