Method and system of controlling a quick succession drive-neutral-drive (d-n-d) shift

A method of controlling a quick succession drive-neutral-drive (D-N-D) shift in a multi-speed transmission, comprising:

• receiving a D-N-D shift, including a drive to neutral (D-N) shift request followed by a neutral to drive (N-D) shift request;
• determining whether the multi-speed transmission is in a process of shifting from an attained gear to a command gear during the D-N shift request;
• determining whether an off-going clutch is in a released state when the multi-speed transmission is in the process of shifting from the initial attained gear to the command gear during the D-N request;
• updating the attained gear equal to the command gear when the off-going clutch is in a released state;
• determining a scheduled gear following the neutral to drive (N-D) request;
• determining if the scheduled gear is equal to the attained gear;
• determining whether an off-going clutch for the drive to neutral (D-N) shift is in a hold state;
• and
• implementing one of the following:
• (I) aborting the drive to neutral (D-N) shift and shifting into one of the attained gear and scheduled gear when (i) the scheduled gear is not equal to the attained gear, and (ii) the off-going clutch for the drive to neutral (D-N) shift is in the hold state;
• and
• (II) completing a shift to neutral (N) when the off-going clutch for the drive to neutral (D-N) shift is not in the hold state followed by shifting from neutral (N) into one of the attained gear and scheduled gear.

A system for controlling a drive-neutral-drive (D-N-D) shift in a multi-speed transmission, comprising:

• a multi-speed transmission;
• a shifter configured to receive a D-N-D shift command;
• and
• a transmission controller in electronic communication with the multi-speed transmission and the shifter, wherein the transmission controller comprises:
• a non-transitory computer readable medium storing instructions to implement a method for controlling a D-N-D shift of the multi-speed transmission, and
• a processor configured for accessing the instructions and implementing the method, wherein the method comprises of:
• receiving a D-N-D shift, including a drive to neutral (D-N) shift request followed by a neutral to drive (N-D) shift request,
• determining a shift abort sequence upon receiving the drive to neutral (D-N) shift request, and
• implementing the shift abort sequence, wherein the shift abort sequence includes one of (i) aborting the shift to neutral resulting in a drive to drive (D-D) shift and (ii) shifting into neutral (N) before shifting back into drive (D).