but i suspect you would want to be close to home when you tried it.

I get the feeling your thinking about some sort of tiptronic setup?

Ive just gone through the 135 page manual for these gearboxes because to be honest its probably the part of a car I know the least about. To summarize what was in there -

As previously posted, S1 and S2 control the gear selection. I was happy to read that the position of these in each gear was the same as what I had worked out, being:

1st gear: Both S1 and S2 on
2nd gear: S2 on
3rd gear: both off
4th gear: S1 on

S3 controls the application of the clutch C1, and S4 controls the front band. Both of these need to be applied in a controlled way for smooth shifting, which is done by S5 controlling the pressure delivered to them while their solenoids are open. The more current delivered to S5, the lower the line pressure. Im a little confused as to how these are used at the moment. In the manual it says the front band needs to be applied while in 2nd and 4th gears, and the C1 clutch applied in 3rd and 4th. But the table above indicates that S3 solenoid (controls C1) is on while shifting into 3rd and the S4 (controlling the forward band) is on during all shifts. Logging what the factory TCU does will tell us how to control it, but I suspect that the solenoids are used for the application of the clutch/band, which then may or may not be held in place by hydraulic pressure depending on the gear.

The remaining clutches C2, C3 and C4 and the rear band (none of which we need to control) receive line pressure regulated by the primary regulator valve. Under light throttle, the line pressure is reduced by switching on S6. Under heavy throttle, S6 is switched off, increasing the line pressure so the gearbox handles the extra torque

Finally, S7 locks the torque converter. On pre-ef 4 speeds, the lockup occurs when in 4th under "suitable driving conditions", which I read as cruise or light throttle. On EF's and onwards and when the gearbox is in economy, lockup occurs late in the 3rd gear and partially disengages for the 3rd to 4th shift. In all gearboxes, the S5 solenoid is again used to provide smooth engagement.

Oh, and reverse requires both S1 and S2 to be on. C3 is locked by hydraulic pressure to reverse the rotation of the output shaft.

I believe the ECU also expects a signal from the TCU. Looks like this signal is 12V to send ECU into LHM, 0V to report a thermistor error, or a 10,20,30 or 40Hz wave indicating the temperature of the gearbox which is used to adjust idle speed.