[zootboy]

Commercial Tier 4F diesels of the John Deere variety have latching fault codes when they relate to the aftertreatment system. It requires the manufacturer's proprietary scan tool (which they will not sell to you) to clear the code, even if the actual issue was something as simple as a connector left unplugged for too long.

[balls187]

Requiring proprietary dongles/software to clear fault codes are not uncommon, but I'm surprised there hasn't been enough interest for there to be a 3rd party tool.

Like McDonald's Shake Machines had a 3rd party tool to help diagnose issues.

[bfdm]

There is interest, but thanks to DMCA 1201 they put a thin veneer of encryption on it and suddenly it's a felony to make/use that third party tool.

[crooked-v]

The McDonald's stuff in particular is a red herring. Their requirements are contract requirements, put in place after too many franchisees tarnished their name with listeria outbreaks.