1.15.11.1 Non-permissible deviations between requested and actual throttle position

P1637 (DVELnpl) 

Throttle position is monitored for non-permissible deviations. If the deviation between the set point and the actual throttle valve position exceeds a calibrated value for a calibrated period of time, a throttle body malfunction will be detected. The system is then placed in the throttle valve default drive function state and a DVELnpl fault will be set.