Disconnecting auto cable for dyno runs - issues?

[BLACKCAT]

Can anyone think of any negative issues with disconnecting the auto cable, at the throttle body, during chassis dyno runs?

With o/d switched off & the cable loosened as far as the thread will allow it still wants to downshift to 2nd at anything under around 90 km/h.
Want to check the A/F ratios & boost level at the lower rpm.

 

[IJ.]

Unplug the ECT and leave it in 2

The cable has NOTHING to do with shift timing.

 

[toyotanos]

If anything you'd want it to be pulled out, not released. It controls throttle pressure in the trans, which boosts line pressure to keep the trans from slipping during full-throttle (high HP) acceleration.
Released/idle=normal line pressure, less drag for good MPG, good for cruising, also provides smoother shifts. May slip under WOT.
Pulled out/WOT=higher line pressure, holds more torque, good for WOT, but makes shifts rough. Not good for trans longevity due to hard shifts/high pressure.

That said, leave it alone.

 

[TurboStreetCar]

Unplug the ECT and leave it in 2

The cable has NOTHING to do with shift timing.

As usual on point with the best answer possible. Before I got my tranny controller I drove with no tranny computer. L becomes 1st, 2 becomes 3rd, D becomes overdrive, lockup is never achieved cause of no signal.