A control module of a vehicle comprises a drive diagnostic module and a hybrid control module. The drive diagnostic module determines a load energy of an accessory drive system of the vehicle and determines a slip percentage of a belt of the accessory drive system based on an engine speed and a motor speed. The hybrid control module determines a requested motor torque based on at least one of the load energy and the slip percentage. The control module controls a motor of the vehicle based on the requested motor torque.