Mercedes-Benz ML350 Operator's Manual page 190

The steering wheel gearshift buttons are
located to the left and right of the steering
wheel.
1 Button, inside: downshift
2 Button, outside: upshift
i
You cannot shift with the steering
wheel gearshift buttons when the
transmission is in position P, N or R.
Downshifting
Warning!
On slippery road surfaces, never downshift
in order to obtain braking action. This could
result in drive wheel slip and reduced
vehicle control. Your vehicle's ABS will not
prevent this type of loss of control.
Briefly press the inside of one of the
buttons 1 on the steering wheel.
The transmission will shift to the next
lower gear as permitted by the shift
program. This action simultaneously limits
the gear range of the transmission
( page 187).
Controls in detail
Automatic transmission
Upshifting
Briefly press the outside of one of the
G
buttons 2 on the steering wheel.
The transmission will shift to the next
higher gear as permitted by the shift
program. This action simultaneously
extends the gear range of the transmission
( page 187).
189