First it is important to understand the distinction between the GEAR that the transmission has selected and the GEAR RANGE that the driver has selected. When gear range '4' is selected by the driver, the transmission control system will automatically shift up and down between 1st, 2nd, 3rd, and 4th depending upon conditions -- but will never shift above 4th gear. Similarly when gear range '3' is selected, the transmission will automatically shift between 1st, 2nd and 3rd gears and will never engage 4th or 5th.<br>
To prevent an upshift from the current gear, the driver needs to know which GEAR is actually engaged by the tranny and which GEAR RANGE has been selected. If the current gear is the top gear of the selected range, the driver should NOT attempt to change the gear range. If the current gear is below the TOP gear of the selected gear range, pull and briefly hold the shift lever to the left stop. <br>
It is useful to understand what happens when the shift lever is pulled left and HELD briefly: If the current gear and gear range match, the next lower gear range will be selected AND the transmission will downshift IF redline will NOT be exceeded; if downshifting will cause the engine to exceed redline then the current GEAR RANGE and GEAR will not change. If the engaged gear is not at the top of the current gear range, the gear range will adjust down until the current gear becomes the top gear of the range. For example if gear range Ã´4Ã¶ is selected and 2nd gear is engaged, pulling the shift lever left and holding briefly will select gear range Ã´2Ã¶ and prevent subsequent upshifts above 2nd gear.<br>
Beware that downshifts are always a possibility. So if the driver chooses to setup in a turn at only 3000 rpm and squeezes the throttle to the floor exiting the turn, the transmission will kickdown.<br>
All of the above discussion relates to the standard MB automatic. The AMG automatics are supposed to be a little different.