I call this "Turtle Hand Enigma" or THE. Usually operators will drive up and ask while holding the lever and say "hey whats this mean?" Waaaay more often this is set by operator than actual problem. Operators will in the beginning complain of unit dropping out of drive and they might see a brief flash of the P22. When this occurs is when i start checking into things further. An application of silicone type grease to connector female before connection to switch helps to reduce this if unit is in a very bumpy enviroment. This being a P code and is related to VCM, the P22 will go away when cause is rectified. If accessible use software and laptop and target the VCM and check F-N-R switch imputs. Probably loose or dirty connection or directional switch. Clean connector and if problem still remains, install an new F-N-R switch.

actually mcfa has a service bulletin out on this code
it states what kevin said about the fast shifting but it also states that if the shifter gets stuck between neutral and either fwd or rev and it detects an open circuit for more than 2 seconds it will trigger this code. There is also a note about the code being generated if the PDS (Presence Detection System) is activated with the seat switch open.

There are a few other detail about checking the circuits related to the direction control system and also it mentions using diagnozer to clear the code out of the history records in the VCM.

I will check out the switch next time I go there. Thanks for your input.

Yes this code is for the shift lever outputs it is detecting both fwd and reverse sometimes if you shift to fast this code will set....can also be a sticking switch in the assembly,usually shifting to neutral first then to desired gear will not have any issues
if it is a mechanical issue with bad switches then the combination switch assembly will need replaced( involves pulling the steering wheel and removing the plastic shrouding around the dash display/steering column) is just 4 screws that hold the assembly in place