[rfdesigner]

And the latest addition to this little project

I measured the PWM ratio of the TCC signal under 'harsh' operating conditions this morning on the way to work.. i.e. lock the TC, set the cruise control to ~80, then approach the bottom of a long hill at 70, engage cruise.. Use the multimeter set to min/max capture mode, and see what the extremes are that the TCM is prepared to go to.

Turns out 2.2V average, or ~15% on, is as hard as it pushes.

So that's what I'll set my TCC override to, to get the TCC as tight as I dare.

Derek

EDIT: oh additional: I found that the gear changes are made by engaging the appropriate solenoid.. note: changes, not selection, UNDER NORMAL OPERATING CONDITONS ALL GEAR CHANGE SOLENOIDS ARE OFF.

Thus If I want to have a PIC work out if the car is in an approprate gear to have the TCC locked I will need it to constantly monitor all gear change solenoid signals and deduce what gear has now been selected.

Solenoids:

1-2/4-5 (one solenoid does both gears).. disengages TCC during change only.
2-3 disengages TCC (fail safe for 3-4 solenoid confusion)
3-4 toggles TCC

Thus: start in 1st or 2nd, then accelerate:

(optional)
1-2 activates.. TCC disengage during change, reengages if ON.. this time it isn't so it remains disengaged.

(started in 2nd if in Winter mode)
2-3 activates.. disengage TCC (fail safe)
3-4 activates.. TCC toggled to ON
4-5 activates.. TCC disengage during change, reengages if ON

decelerating:

4-5 activates.. TCC disengage during change, reengages if ON
3-4 activates.. TCC toggled to OFF
2-3 activates.. disengage TCC (fail safe)

(if in Summer Mode)
1-2 activates.. TCC disengage during change, reengages if ON.. this time it isn't so it remains disengaged.

TCC modulation from TCM is modulated to control slip to a specific amount, so will need to allow TCM to modulate faked slip via it's TCC signal. Sounds complicated, but in fact it's easy.

Oh, and the TC is a single fluid clutch + mechanical clutch with friction plates that it allows to slip under 'lock' hence my inclination to push the control signal as far as I dare and hopefully reduce slip to zero... the TC has worn out once already.. that's with the MB setup.