I think one could use an LED and source it via the control circuit for the solenoid. One should be able to run it parallel with the solenoid. I've thought about this for a gear indicator as well as the TC lockup. The gear indicator would be a little more involved since you have 2 shift solenoids for 4 gears. But with some logic relays, it should be able to be done.
FYI, the PCM controls the TCC solenoid by switching the ground circuit for the solenoid. The PCM feeds 12V to the solenoids full time with the key in the start/run positions.
I can't find any solid info on this anywhere other than people do it.
The Info Panel uses software to monitor the voltage and will display a U for unlocked and a L for locked on the VFD screen and the LED Display. The EEC-V FTE1 tune has the ability to modulate the TC slip and it does this a normal routine in 3rd gear at low TPS numbers where it is set to slip at 20. A case could be made to remove this slip setting to prolong TC Clutch life.
A Scan Gauge II will display TC Lockup (TC in/out speed ratio) if the PID is loaded.
Last edited by Winston; 06-08-2009 at 07:17 AM.