Lexus IS sudden acceleration problems

Filed Aug 14, 2025 · Brakes, Electrical · AZ · crash

My car experienced sudden unintended acceleration. I was at a stop light preparing to turn right when my car accelerated of its own accord crashing into the vehicle in front of me. My foot was firmly on the brake, but I had lost control over the vehicle. Whatever electrical defect I experienced, it was sufficient to rev the engine by itself and override the braking system enough that the vehicle advanced forward in an out-of-control manner. It was unintended, unexpected and beyond my ability to control. Failing to recognize the braking system, my vehicle collided into the vehicle a second time. Because my foot was on the brake and my vehicle still advanced forward, I initially thought I had been hit from behind. However, the erratic RPM behavior and the vehicle's continued acceleration while braking confirmed I was no longer in control of the vehicle. Acting promptly, I immediately took the gear shifter out of drive and put into neutral. It was then and only then that I regained control of the vehicle: it stopped accelerating, stopped revving of its own accord and began responding to the braking system. Please note: my foot was not on the gas pedal, for as soon as I took it out of drive, the RPM returned to normal (i.e. the erratic behavior indicated by the tachometer's RPM, stopped). Had my foot been on the gas pedal instead of the brake pedal, the revving would have continued to behave as before; but it did not. (I do not have an all-weather floor mat. It is neither here nor there, because in the event that I did have one, you would expect the RPM behavior to continue when put into neutral; but again, all behavior returned to normal when the vehicle was put in neutral.) Though I am sympathetic to those that panic in a moment of distress, I was of a present enough mind to know what was happening. An electrical engineer with intimate knowledge of the computer system for this vehicle would be the best to assess what went wrong from a technical perspective.

Filed Oct 3, 2023 · Brakes, Engine · CA

On Friday, September 15, 2023 3:00PM, I had a “horrible” experience with my Lexus this weekend and sudden unintended acceleration. I was sitting at a red light, with my foot on the brake. Without warning the engine began to rev, the tires squealed and the car lurched forward. I through the car into park & turned of the car as quickly as I could react and “thank god” no one was injured and there was no accident. I was in the car with my wife and she reminded me she had a similar experience a month ago. I didn’t know what to think when she told me. Until I experienced it myself I didn’t really understand how dangerous this problem is. She experience this sudden unintended acceleration when the car was in park after she got in the car and started it. I’ve read of this sudden unintended acceleration but never experienced it until this weekend. It was exactly this.. an unintended, unexpected, uncontrolled acceleration of a vehicle, accompanied by an apparent loss of braking effectiveness. This was not driver error. It is some kind of mechanical, software problem, electrical problem, or some combination of these factors. There was no driver error. This is not an issue with the floor mats. I drove the car home into the garage. I took it to the dealership the first available appointment on Monday. I had another incident on Wednesday, August 30, 2023. I was at the gym. My wife went to move my car as my parking time limit in La Jolla had expired. She experience sudden unintended acceleration when the car was in park after she got in the car and started it. The car had high engine revs and the car lurched forward while in park. The Lexus Dealership kept the car for a week. Mileage 67,249 Vehicle Report - [XXX]. Reviewed and analyzed by Lexus Factory. No recommended repairs are needed or required at this time. I opened TAS Case# [XXX] . I contacted Lexus Product Liability Team Case # [XXX] but, no one from corporate will look at the car. What should do? [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION

Filed Feb 20, 2020 · Acceleration, Steering · 66,000 miles · IL · crash

Sudden acceleration when trying to stop

Filed Jan 27, 2020 · Body, Brakes · 40,000 miles · AZ · crash

The vehicle has lunged forward while slowing down or at very slow speeds, and the brakes do not operate effectively. The brake is always pressed down as far as it goes without avail. There is no precursor as to when it will happen. In total, the engine lunged forward about 6 times. The first time I nearly hit a vehicle with my minor daughter in the car. The next few times were not as significant in terms of eminent damage. The next incident was worse. It happened in july of 2019 in a drug store parking lot. I was parking in a stall and the vehicle sped up, squealed the tires, jumped the cement parking block, hit some bushes, and I was able to stop it. On this occasion there was damage to my vehicle. There are dents and scratches from the bushes, a tire sensor or two is not functional anymore, and the underbody was damaged. I was thoroughly scared and afraid was car would continue to do this and I could hurt someone. I was able to stop the vehicle only by putting it in park. The brake was rendered useless. It happened twice on the same day in january of 2020. I was driving slowly and it lunged. I was able to slow it down. I proceeded to park the vehicle. Once again it lunged forward at a concrete parking stop. The brakes did not work. I had to put it in park as the only way to stop the vehicle and prevent further damage. All incidents were in a city driving showily. The vehicle had approximately 40,000 miles on it wheni first noticed the safety concern. The vehicle now has approximately 60,000 miles.

Filed Jul 31, 2019 · Acceleration, Transmission · 123,000 miles · CA · crash

I bought 2008 lexus is250 with 123k miles on 05/18/19. I had inspected by a mechanic prior to purchasing it. On one ocassion pror to accident, I backed out of a drive way. When I shifted the automatic transmission from reverse to drive it sudden accelerated for a brief moment, but it was clear in front of me and I remain in control. It only happened to me that one time that week and I thought nothing of it. In the morning of may 29, 2019 the car was parallel parked with a vehicle both in front behind it. My wife slowly back up the car to allow room to pull out of the parking spot. She turn the front wheels towards the curb so that the front of the car would slightly stick out. When she shifted the automatic transmission from reverse to drive, the car suddenly accelerated, jump over the curb and hit the concrete wall of a school. She panicked at the sudden acceleration and does not remember if she step on any pedal during that time. She only knows it accelerated as soon as she shifted to drive and then the car hit the wall. There were no injuries and no other car was involved. We moved the car off the side walk and notified the insurance and the school admin.the insurance declared it a total loss and took ownership of it. A gasoline car accelerate by opening the throttle to allow more air into the engine. The electronic throttle suddenly open due to the physical electronics and/or software controlling it when the transmission is shift between reverse and drive. Dr. Ronald a. Belt theory seems plausible. If true you would think just changing the software to get an average of voltage samples would prevent the over compensation of the ecu throttle controller cause by low voltage spikes. Https://www.autosafety.org/dr-ronald-a-belts-sudden-acceleration-papers/

Filed Jul 14, 2015 · Acceleration, Airbags · 23,000 miles · CA · crash

My lexus 2012 is 250 accelerated on its own, brakes did not engage after depressing them x2, and then I crashed into a truck. Air bag did not deploy. Reported to lexus who assumed no responsibility for incident. Third party inspected car and downloaded black box. Report from lexus stated that car was drive able and no issues were found. Car incurred $18,000 in damages and was not drivable at the time of inspection. Witnesses at collision shop will validate such. When speaking to representatives at lexus to report incident I was told by 2 reps on 2 occasions that this has happened to other vehicles that were the same make and model. Disturbing

Filed Nov 15, 2012 · Acceleration, Brakes · 16,911 miles · MN · crash

Daily driver of the vehicle for two years was easing into a parking space and applying the brakes when vehicle surged forward over a curb eventually crashing into a tree. After the vehicle went over the curb it went through a chain link fence and down a steep embankment leading to a great deal of chaos and confusion as to whether the brakes continued to be applied, but the driver is confident that the brakes were being applied when the initial surge occurred. The driver's spouse experienced a similar event about a month earlier when driving about 2 MPH down a long driveway. In this instance the engine revved to a higher speed when the brakes were applied but the brakes did stop the car before the engine speed returned to normal.

Filed Mar 5, 2010 · Acceleration · 30,658 miles · FL

Tl* the contact owns a 2009 lexus is250. The contact stated the vehicle was taken in for routine maintenance, vibration in the steering wheel and also for unintended acceleration at any speed. The dealer road tested the vehicle and found a faulty left wheel bearing and hub assembly that causes excessive noise and vibration which they repaired. The contact stated he inform the dealer that the accelerator pedal was sticking and to check on it but was told they are not going to repair is250 accelerator pedals until the next three months. The car was given back on march 4 without checking the failure. While driving the vehicle it accelerated at high speeds of more than 106mph, when this happened the contact was trying to stop the vehicle by pulling the emergency brake, pulling on the gas pedal, hitting the push button that starts the vehicle and then trying to get off on the side of the road.meanwhile the motor is revving at a high speed. There was a police trooper who saw this but gave him a ticket because he thought he was speeding. The contact stated after he got home she notice the accelerator pedal was stuck to the floor while the vehicle motor was racing at a high speed. The lexus dealer was called and they would have the vehlcle towed to the dealership. The failure mileage was 30,658.

Filed Feb 19, 2010 · Acceleration · 11,000 miles · GA · crash · 1 injury

Tl*the contact owns a 2009 lexus is 250 . He stated that while driving 35 MPH up a hill when turning and slowing down by putting his foot on the brake pedal the vehicle accelerated on its own. The vehicle accelerated and crashed over a mountain. The contact sustained major injuries, broke his right shoulder, chest pains, and his face was also injured when the air bag deployed hitting him in the face. The police and the insurance company were contacted and a report was filed by both of them. The vehicle was towed to a local towing facility where they stated that the vehicle was destroyed. The dealer was contacted and wrote a report as well. He also stated that he received a recall notice for the floor mats and was waiting for an appointment. The failure and current mileage were 11000.

Filed Nov 26, 2009 · Acceleration · 5,000 miles · MD

In early 02/09 I was driving home on interstate 695 n in maryland. I was traveling about 50 MPH, when all of a sudden the car suddenly accelerated to about 95 MPH through no effort of my own. I did not engage the accelerator pedal to increase the speed of the vehicle. I immediately engaged the foot brake to decelerate and but the car would not slow. Eventually after several attempts I was able to slow the car with the brake but the engine continued to violently rev. As I released the foot brake, the car once again accelerated without engaging the accelerator pedal. Even after engaging the emergency brake, the unaided acceleration and my attempt to decelerate the car continued. I was finally able to slow the car enough to pull out of traffic and over to the emergency lane and eventually stop the motion of the vehicle. Although I was able to bring the car to a stop, the engine continued to rev violently, the back tires spun out of control and the back of the car started to fish tail. I tried a number of different tactics to stop the car completely including, attempting to manually shift gears, putting the car in neutral etc. Finally, after several minutes I was able to turn off the ignition and bring the car to a complete stop and the ordeal came to an end without damaging the car and more importantly without injury to me or others. I had the car towed to dealership that night and explained the situation to the service organization the following day. The service team conducted multiple diagnostic tests but was unable to determine or explain the cause of the unintended acceleration to my satisfaction. One service rep suggested that the floor mat was the cause but I had checked immediately after the ordeal the night before to ensure that the floor mat had not become lodged under the accelerator pedal. Since the dealership was not able to determine the cause of the problem, I decided that the best course of action was to return the car and lease another car.