Acura 2009 TSX Owner's Manual page 392

Driving with the Paddle Shifters
Downshifting with the paddle shifter
allows you to increase the engine
braking when going down steep or
long hills, and provides more power
when climbing uphills. You can
upshift the transmission manually to
reduce the rpm. Driving in the
higher gear helps fuel economy.
The transmission also shifts
automatically as the vehicle comes to
a complete stop. It downshifts to first
gear when the vehicle speed reaches
6 mph (10 km/h) or less.
386
The automatic transmission will not
allow you to shift up or down if:
You downshift before the engine
speed falls below the upper limit of
the lower gear.
If you try to do this, the gear
position indicator will flash the
number of the lower gear several
times, then return to a higher gear.
If the vehicle speed decreases
below the redline of the selected
lower gear while the indicator is
flashing, the transmission
downshifts, and the indicator
displays the selected gear.
You upshift before the engine
speed rises above the lower limit
of the higher gear.
You press both paddle shifters at
the same time.
Here are the speed ranges for
upshifting and downshifting.
To shift Speed range
from
1 2 over 0 mph (0 km/h)
2 3 over 6 mph (10 km/h)
3 4 over 20 mph (32 km/h)
4 5 over 32 mph (52 km/h)