NHTSA Complaint #10318625 — 2002 TOYOTA PRIUS

2002 TOYOTA PRIUS BRAKING PROBLEM*CW THE CONSUMER STATED HE DIDN'T SEE THE ISSUE AS A BRAKING PROBLEM; RATHER A CONTROL CONFLICT. WHENEVER THE PROBLEM OCCURRED, THE VEHICLE WAS MOVING DOWN A SLIGHT GRADE ON A ROAD SURFACE HAVING ITS SHARE OF PAVING PATCHES, FROST HEAVES, ETC. THE SLIGHT DOWNGRADE CAUSES THE VEHICLES SPEED TO INCREASE, OR PERHAPS AN INTERSECTION APPEARED AHEAD AND FOR WHATEVER REASON THE BRAKES WERE GENTLY APPLIED IN ORDER TO SLOW THE VEHICLE DOWN. WHEN THE PROBLEM OCCURRED, THE SYMPTOM WAS A BRIEF INTERVAL AND THE VEHICLE SEEMED TO ACCELERATE AND THEN NORMAL BRAKING RESUMED AND THE VEHICLE SLOWED DOWN. JUST PRIOR TO THE BRAKE ACTIVATION, THE VEHICLE IS IN REGENERATION MODE, IN WHICH THE ELECTRIC PROPULSION MOTORS ARE ACTING AS GENERATORS, WHERE ENERGY MOTION IS BEING EXTRACTED AND CONVERTED TO ELECTRICAL ENERGY TO BE STORED IN THE VEHICLES BATTERY. WHENEVER THE BRAKE PEDAL IS ACTIVATED, THE FIRST THING THAT HAPPENS IS THAT THE MOTOR NOW BECOME GENERATORS ARE FORCED BY THE CONTROL SYSTEM TO CONVERT SIGNIFICANT ENERGY OF MOTION INTO ELECTRICAL ENERGY. THE CONSUMER BELIEVED THAT THE NORMAL BRAKING SYSTEM SHUTS DOWN. THE CONSUMER BELIEVED THE PROBLEM WAS WITH THE ABS.