a complementary regenerative torque system exists for a vehicle including an engine having an accelerator pedal position sensor ; a transmission unit ; and a drive shaft for driving a pair of wheels for propelling the vehicle . the regenerative torque system selectively stores and supplies energy to the drive train to provide on demand complementary torque thereto . the regenerative torque system may be either hydraulic or electric in nature and may be disposed upstream or downstream of the transmission relative to the engine . a regenerative torque control module is disposed between the accelerator pedal position sensor and the engine control module and intercepts the accelerator pedal position signal and modifies it in response to the mode of operation of the regenerative torque system and forwards the modified throttle signal to the engine control module . likewise , the regenerative torque control module intercepts signals from the engine control module and modifies the same prior to broadcasting them to the rest of the vehicle &# 39 ; s control modules .