>couldn't always be solved by power cycling the vehicle.

From experience, I've found that turning a car off is akin to putting a computer to sleep. If the state is fubar, no amount of turning the car on and off will fix it.

The only proper way to "power cycle" a car is to momentarily disconnect the car battery (remember to turn the car off first) so all power to the computers are physically cut off and they /have/ to start from a cold boot next time you turn the car on.