the ecu determines the rpm that the VTEC will engage.
it is based on several factors that the ecu is monitoring
the stock cam changeover for the h22 is between 5000 and 5500
it is not a fixed number

the intake air temp
the coolant temp
VSS input (wheel speed)
head oil pressure
knock sensor
and several other variables the the honda calls "ecu calculated engine load" (basically fuel and timing settings)

determine when the VTEC will engage

btw what turned out to be the problem with code 22?
im curious, was it wiring

~kris