2017 Toyota Prius Speed Control & Cruise Problems

On 10/16/23 I was turning slowly into a parking spot and my car suddenly accelerated without my pressing the accelerator. I slammed on the break and the car stopped. It was frightening because I could have hit someone or something but luckily the car stopped before that happened. I believe that this was a malfunction of the accelerator. This has not been checked or reported to anyone yet but I will be calling Toyota to have it checked. There have been no warning messages.

I had just changed from the right-hand lane to the center lane of a six-lane expressway when my vehicle lost power and i was able to move over to the right hand shoulder of the road. The accelerator pedal did not work and I just coasted to the side of the road. I noticed that a red warning saying something about RADAR flashed on the instrument panel when this happened. I turned off the vehicle and tried to restart it, but nothing happened. I then texted the person who was expecting me and explained the problem. Since I had just taken the car to the dealer for its regular 40,000 mile service four days earlier, I intended to call my dealer to ask them what to do. All of this took about 10 minutes with the engine turned off. Before doing this, I again tried to restart it. It started and I inched it forward on the shoulder of the road. Since I did not feel safe parked on the shoulder, I merged into traffic and took it to another Toyota dealer. They said that they could not look at my vehicle to diagnose what might be wrong because all their technicians were going home at 4 pm. I drove to my son's house and he suggested that I report this to you. Something similar happened to him when he was driving this same vehicle about six month ago. He was driving on a city street, did not notice any dashboard warning, and took it to this same dealer. They were not able find anything wrong. I felt I should report this since this is the second time this vehicle suddenly lost power. My incident happened when I was driving at expressway speed and could have caused a serious accident had I not been able to coast to the shoulder of the road.

For the second time (first in 2019) I was seconds and maybe two feet from stopping the car to park when, with my foot on the brake, the car suddenly and without warning lunged forward at what seemed like full throttle. The first "crash" was in my driveway. The force was shocking and took off the front of the car. I insisted Toyota investigate and they ultimately denied any liability. After the car was allegedly repaired, I started noticing another phenomenon: every time I would slow down to brake--approaching an intersection or stop sign, etc.--the car would briefly lunge forward before the brakes engaged to stop the car. I reported this to the dealer 2-3 times and each time I was assured that this was "normal" for a hybrid transitioning from gas to electric at a lower speed. Two weeks ago, with a friend in the car, I was pulling into a parking space, foot on the brake and about to stop, when the same thing occurred: without warning, the car lunged forward, at what seemed like full throttle, and crashed into a low concrete wall. Had it been seconds later, we would have had our seatbelts off and gone into the windshield. There were injuries. FYI, I have a pretty much perfect driving record and log thousands of miles each year. I had ZERO problems with the Prius I owned prior to this one. I will never drive this car again.

TL* THE CONTACT OWNED A 2017 TOYOTA PRIUS. WHILE THE CONTACT WAS REVERSING THE VEHICLE INTO A PARKING LOT, IT ACCELERATED WITHOUT WARNING. THE CONTACT ATTEMPTED TO DEPRESS THE BRAKE PEDAL, BUT IT FAILED TO ENGAGE AND CAUSED THE VEHICLE TO CRASH INTO A TREE. ALL THE AIR BAGS DEPLOYED. THE CONTACT DID NOT ENGAGE THE EMERGENCY BRAKE. THE CONTACT AND PASSENGER SUSTAINED MINOR INJURIES AND RECEIVED MEDICAL ATTENTION. A POLICE REPORT WAS NOT FILED. THE CONTACT'S INSURANCE COMPANY TOWED THE VEHICLE TO A LOT AND DEEMED IT A TOTAL LOSS. THE DEALER AND MANUFACTURER WERE NOT CONTACTED. THE CAUSE OF THE FAILURES WAS NOT DETERMINED. THE FAILURE MILEAGE WAS APPROXIMATELY 13,850. *LN*JB

I HAD AN SUA (SUDDEN UNINTENDED ACCELERATION). I DROVE UP AN INCLINE INTO THE "DRIVEWAY" OF THE HOLIDAY IN IN DOWNTOWN SAN DIEGO, PULLED UP INTO A SMALL CIRCULAR AREA/DRIVEWAY WHERE YOU CAN REGISTER FOR YOUR ROOM OR PICK UP OR DROP OFF PEOPLE. MY FOOT WAS ON THE BRAKE, I WAS STOPPING THE CAR TO PICK UP MY DAUGHTER AND HER BOYFRIEND. AND THE CAR TOOK OFF ON IT'S OWN. I TRIED DESPERATELY TO USE THE BRAKES, BUT THEY WOULDN'T WORK, SO I KEPT DRIVING AROUND THE CIRCULAR DRIVEWAY TO KEEP CONTROL OF THE CAR WHILE I KEPT TRYING TO STOP THE CAR TO NO AVAIL. THE CAR KEPT ACCELERATING AND SCREECHING AROUND THE DRIVEWAY AND THEN I FINALLY LOST CONTROL AND THE CAR HIT A WALL TO MY RIGHT, THEN MOVED A BIT FORWARD AND BUMPED INTO A CURB ON THE LEFT AND FINALLY STOPPED.MY OTHER DAUGHTER WAS IN THE PASSENGER SEAT.WE WERE BOTH TERRIFIED! I CONTACTED TOYOTA AND FROM THE TIME OF THE ACCIDENT (10/28/19) TO THE TIME I WAS ABLE TO TALK WITH A PERSON IN THEIR CLAIMS DEPT OR RATHER RECEIVE AN EMAIL RESPONSE, IT WAS 64 DAYS LATER (10/31/19). AND THAT IS ONLY BECAUSE I CALLED THEM. I TALKED TO SEVERAL CASE MANAGERS ON DIFFERENT DAYS WHO SEEMED UNHELPFUL UNTIL FINALLY ONE OF THEM GOT IN TOUCH WITH THE CLAIMS DEPARTMENT AND TOLD ME THEY WOULD CALL ME. TOYOTA WILL NOT TAKE ANY RESPONSIBILITY FOR THIS AND I AM REALLY UPSET THAT NOW I WILL HAVE AN ACCIDENT ON MY RECORD AND MY INSURANCE WILL INCREASE SIGNIFICANTLY FOR SOMETHING THAT ISN'T EVEN MY FAULT! I AM AN EXCELLENT DRIVER AND HAVE NEVER HAD AN ACCIDENT THAT WAS MY FAULT. I WAS ALERT AND COHERENT AS WAS OBVIOUS TO ALL OF THE PEOPLE I SPOKE TO DIRECTLY AFTER THE ACCIDENT. MY DAUGHTER, IN THE PASSENGER SEAT, WITNESSED ALL OF MY ATTEMPTS TO USE THE BRAKES TO STOP THE CAR.

2017 TOYOTA PRIUS. CONSUMER WRITES IN REGARDS TO UNINTENDED ACCELERATION. *LD THE CONSUMER STATED THE VEHICLE ACCELERATED AND THE BRAKES WERE UNRESPONSIVE RESULTING IN A CRASH. THE CONSUMER WAS INJURED AND REQUIRED MEDICAL ATTENTION. *JS *JS

IN MODERATE TO HEAVY RAIN WITH THE TOYOTA DYNAMIC CRUISE CONTROL ENGAGED ON THE HIGHWAY BETWEEN 55 AND 70 MPH, THE PRIUS HAS DANGEROUSLY ACCELERATED ITSELF TOWARDS A CAR IMMEDIATELY IN FRONT OF MY CAR AND WOULD HAVE CREATED A FRONT-TO-REAR COLLISION IF I WAS NOT EXTREMELY VIGILANT AND MANUALLY BRAKED AND CANCELED THE ADAPTIVE CRUISE SYSTEM WITHIN 10-20 FEET OF THE CAR IN FRONT OF ME. THE SYSTEM SEEMS TO OPERATE BLINDLY IN MODERATE TO HEAVY RAIN AND WILL ACCELERATE TO USER-SET SPEED EVEN WHEN A CAR IS TRAVELING SLOWER IMMEDIATELY IN FRONT OF MY VEHICLE. I STRONGLY SUSPECT THE PRE-COLLISION BRAKING IS FAILING AT THE SAME TIME AS THE DYNAMIC CRUISE (IN RAIN) SINCE IT RELIES ON THE SAME COMPONENTS. THE PRIUS PRIME NEEDS TO BE REPROGRAMMED TO NOT ALLOW DYNAMIC CRUISE ENGAGEMENT IN MODERATE TO HEAVY RAIN. THIS IS A VERY DANGEROUS SITUATION BECAUSE DRIVER VISIBILITY IS ALREADY IMPAIRED UNDER THESE CONDITIONS. IF THIS DID NOT OCCUR MULTIPLE TIMES, I WOULD NOT HAVE BELIEVED IT WAS ACTUALLY HAPPENING. THE PRIUS MANUAL SAYS THAT RAIN CAN CAUSE THE SYSTEM TO NOT BEHAVE AS INTENDED; HOWEVER, IN THAT CASE IT NEEDS TO BE AUTOMATICALLY DISABLED SO IT DOES NOT CREATE A VERY FALSE SENSE OF SECURITY. THIS IS GOING TO COST LIVES IF IT'S NOT REPROGRAMMED. I WOULD BE SURPRISED IF THIS WAS THE ONLY TOYOTA THAT EXHIBITS THIS DANGEROUS BEHAVIOR. I STRONGLY BELIEVE THAT LIVES CAN BE SAVED WITH A SIMPLE REPROGRAM OF THE SYSTEM TO NOT ALLOW OPERATION UNDER CONDITIONS THAT CAN CREATE UNINTENDED ACCELERATION INTO A SLOWER MOVING VEHICLE. TOYOTA SHOULD SAVE THEMSELVES MILLIONS IN POTENTIAL LIABILITY AND TAKE THIS SUGGESTION SERIOUSLY.

WHILE DRIVING ON INTERSTATE HIGHWAY IN HEAVY TRAFFIC USING CRUISE CONTROL MY CAR SUDDENLY ACCELERATED QUICKLY. WEATHER WAS ALIGHT RAIN. IT WAS LIKE THE RADAR FOR THE CRUISE CONTROL SHUT OFF OR STOPPED BEING PROCESSED.

THE ADAPTIVE CRUISE CONTROL IN THIS VEHICLE HAS SEVERAL OPERATIONAL ISSUES (PROGRAMMING BUGS OR DEFECTS) WHICH ARE POTENTIALLY EXTREMELY HAZARDOUS. PERHAPS THE MOST POTENTIALLY DANGEROUS BEHAVIOR OF THE SYSTEM IS AS FOLLOWS: - WHEN USING ADAPTIVE CRUISE CONTROL, THE SYSTEM AUTOMATICALLY ACCELERATES AND APPLIES BRAKING FORCE TO STAY A SET DISTANCE (ONE OF THREE DISTANCES) FROM THE NEAREST PRECEDING VEHICLE. - WHEN THE NEAREST PRECEDING VEHICLE CHANGES LANES, THE SYSTEM CAN BECOME CONFUSED, DISPLAY "NO PRECEDING VEHICLE" AND DISENGAGE. - THIS BEHAVIOR CAN BE DANGEROUS OR LIFE-THREATENING IN SOME CASES, WHICH I'VE EXPERIENCED SEVERAL TIMES: WHAT HAPPENED: - HIGHWAY DRIVING AT 65MPH, USING ADAPTIVE CRUISE CONTROL AND FOLLOWING ANOTHER VEHICLE. - WE APPROACH AN AREA OF CONGESTION OR STOPPED VEHICLES (A TRAFFIC JAM). - THE PRECEDING VEHICLE BEGINS QUICK DECELERATION IN ORDER TO AVOID REAR-ENDING THE VEHICLE IN FRONT OF IT. - MY ADAPTIVE CRUISE CONTROL ALSO APPLIES STRONG BRAKING TO MAINTAIN ITS PROGRAMMED DISTANCE - THE PRECEDING VEHICLE CHANGES LANES OUT OF MY LANE - MY ADAPTIVE CRUISE CONTROL DISPLAYS "NO PRECEDING VEHICLE" AND DISENGAGES, WHICH MEANS THAT IT STOPS BRAKING - MY CAR IS NOW FLYING INTO THE VEHICLE IN FRONT OF ME, GIVING ME ONLY A MOMENT TO REACT AND APPLY BRAKING. INSTEAD OF DISENGAGING DURING BRAKING, THE ADAPTIVE CRUISE CONTROL SHOULD CONTINUE BRAKING DOWN TO A SPEED OF 25MPH, WHICH IS THE MAXIMUM SPEED THAT TOYOTA'S SAFETY STOP OPERATES AT TO BRING A CAR TO A COMPLETE STOP. THE CURRENT BEHAVIOR OF THE SYSTEM HAS LED TO SEVERAL NEAR ACCIDENTS IN MY HIGHWAY DRIVING, AND IS UNDOUBTEDLY A DANGER TO ANYONE ELSE WHO USES A TOYOTA ADAPTIVE CRUISE CONTROL OF THIS MODEL ON THE HIGHWAY. I REPORTED THIS ISSUE TO TOYOTA LAST YEAR AND THEY SEEM UNINTERESTED IN FIXING IT, REFUSING EVEN TO CONVEY MY REPORT TO THEIR DEVELOPERS IN JAPAN.