Convertor is now jumping in and out of lock-up while driving down the highway at 65mph. Hooked up my voltmeter across pins A and F. I see 13.2 volts when the convertor is not locked up and 0 volts when it is. This change in voltage corresponds with the convertor jumping in and out of lock-up when driving. I think this pretty much eliminates the torque convertor as the culprit. As I see it, it could be the computer, temp. switch, brake switch, or maybe something else I'm not aware of that is in the circuit.
I'm wondering if anyone else has been through this one and can offer some advice.
Thanks!

 

Replace the CTS sensor and clean up the connector real good. I had this problem where the sensor was loose inside (cracked wire) and the only way I found it was to datalog at 15hz. I'd see a spike in the cts and sure enough that was it. It never set a code (not long enough to trigger the diagnostic) and the normal 160baud aldl wasn't fast enough.
Check that first, I figure I'd just let you know that can be a culpret that is hard to diagnose... good luck. Without tcc I think I'd go crazy.

 

No expert for sure, but you should have constant 12V to the converter, the ECM sends a grounding signal to complete the circuit. There is probably a pressure switch inside the tranny on the valve body that gives the ECM a fourth gear signal too, but with the erratic power supply, I'd start with that.