Hello, I’m new to trucking and I drive a 2012 Volvo d13 670 vnl. I know this will be a stupid question to all. I have the M on my shifter but I don’t have the up or down buttons for me to chose my own gears. Did they in this year not do the ishift or my model didn’t include it. Just wondering thank you.
The manual option is to hold the truck in gear for down hills & RxR tracks. Whoever spec’d the truck was a cheapskate & bought the most basic transmission option.
On the Volvo you describe, I had one, you can "lock" into your current gear by selecting M, but you cannot upshift or downshift. The transmission will eventualy change into higher and lower gears even while in M if your RPMs get too far out of range.
Also, regardless if your truck has a switch to put the transmission into auto or manual mode, that feature can be disabled in the ECM.