Study on Creep Function of one P1P4 Vehicle with Torque Converter

The creeping speed of vehicles with torque converter varied with the engine idle speed. In traditional vehicles, it happened on cold engine or transmission condition obviously. But in P1P4 hybrid vehicles, due to more engine start and stop and power regeneration, the engine water temperature was not easily to keep over 90°C, which lead to higher engine idle speed when engine was on. Thus, due to the impeller pump torque varying with engine idle speed, the creeping torque changed, which lead to the inconsistency of vehicle creeping speed. In P1P4 target vehicle, a new software was developed to solve this problem with new torque split. After verification and calibration, the new software was released.