the only code im getting is the slippage code. once reset, it only shows up after driving uphill in OD. so for now as soon I go uphill, I turn OD off.
and yess, A&E and a Transmission sensor , neither see a lock code.. but my jumper don't work either at the moment, so im ohming out the harness and solenoids this eve.

 

I'm not familiar with your scanner or diagnosing your transmission with the scanner. It seems like others are kinda confused by what you are telling them too. Can you hook up your scanner to a working truck and see if it gets the results you are expecting?

Either way it is an interesting thread I'll look forward to reading what you find.

 

maybe I should recap:

While going uphill one day at about 50MPH, no load, the TC dropped out and the OD Light came on.
- checked error code with my AutoEnginuity Software (A&E) and had a 1728 Code.
- Transmission Shop checked with a live data transmission scanner, and noticed the TC does not get a lock Code from the PCM but also seen a extremely high Coolant Temp on the read out. (I have a manual gauge for temp and the one in the dash is disconnected)
- Re verified with A&E software at home.. started thread with Coolant temp ..
- found out, Coolant temp is not reported to the PCM and this is just a bogus / random number.
- checked and repaired 3rd brake light, as this could have an impact of why the PCM is not sending a code. No change on my problem
- unplugged the Tuner... no change
- I can drive the Truck, but once going Uphill I have to turn it in Tow mode, or the OD light comes back on and I have to reset it again.
- checked TC on outside visually for oil (frontseal) and for any signs of overheating.. but looks good.
- checked plug on transmission visually and looks OK.
- used jumper wire and switch to bypass the PCM and lock in TC manually. spliced the jumper to the harness right below the brake booster. still no TC Lockup.

I can only do a little bit a day, due to weather and getting home late.
Next step will be Ohming out the Transmission Solenoid Pack on the wire on the transmission. If I get a reading there, I will check the harness back to my jumper.
Questions:
- will I hear each solenoid with the Key on, if I jumper them out ?
- if pack is bad, anyone has a good solenoid pack or knows where best to buy one that is not expensive?
- can anybody confirm: If the PCM does not "see" the solenoid, (resistant check ?) , the PCM will send no lockup signal.

thanks