1.15.11.2 Duty cycle range check

P1639 (DVERmax), P1638 (DVERmin) 

If the duty cycle of the digital position controller exceeds a calibrated maximum or lies below a calibrated minimum for a long period of time T2, a duty cycle malfunction (and hence an actuator current malfunction) will be detected. The system will then be placed in the throttle valve default drive function state and a DVERmax fault will be set.

If the duty cycle exceeds the calibrated maximum or lies below the calibrated minimum for a calibrated period of time T1 that is much shorter than T2, the system will request a brief deactivation of fuel injection and a DVERmin fault will be set.