2017 Tesla Model S: adaptive cruise control problems

Filed Aug 24, 2025 · Electrical, Lights · NJ

Tesla originally confirmed issues with the MCU1 system in my vehicle and upgraded it to MCU2. I Paid $1,599 for the repair/upgrade. Since then, the center screen has continued shutting off while driving. When this happens, the instrument cluster and controls go dark, I cannot see my speed, use the blinkers to signal, operate the AC/defroster, or access other critical vehicle functions. This has occurred multiple times on highways, including US-22 in New Jersey, which created serious danger because I could not monitor speed or signal properly. Although Tesla addressed the MCU1 problem by upgrading me to MCU2, they told me afterward the vehicle was still “safe to drive,” despite the failures continuing. I believe this is unsafe because I lose visibility of all driving information and access to basic controls. Tesla now refuses to repair these ongoing problems. After I raised complaints about the severity of the issue, I was dismissed and mocked for my speech disability during phone calls, and Tesla placed me on a service restriction. As a result, I am unable to obtain further repairs for this safety defect. I am afraid to drive the car. No Adaptive Cruise Control, Automatic Emergency Braking, Blind Spot Warning, Forward Collision Warning, Lane Departure Warning, Lane Keeping Assistance, Parking Collision Warning, or Rear Cross Traffic Warning features were involved in this failure.

Filed Nov 10, 2023 · Driver assistance · IL

5 times on a cross country trip, I experienced the phenomenon of "phantom braking" . As I was driving with Adaptive Cruise on, doing approximately the speed limit, the brakes were automatically applied and the car started to rapidly slow down. Luckily there was no one behind me so I was not rear ended ! I immediately took the car to the local Tesla service center thinking there was a problem with the car, but they told me this is a know issue with no solution at present. One tech told me he has a Tesla himself and has experienced the same issue ! He told me that he just punches the accelerator and keeps on driving !

Filed Jul 16, 2023 · Brakes, Driver assistance · CA

During a road trip (May 2023) with cruise control activated, I had at least 5 phantom braking events. The most serious was in Las Vegas on the freeway with a very severe braking event. I now no longer use cruise control in crowded traffic so that I won't get rear ended when a phantom braking event happens.

Filed May 26, 2023 · Driver assistance · KS

When using the automated cruise control or full self driving, it will unexpectedly phantom brake. Seems to happen more when there is full sun. I have the latest updates. Did much better when cloudy, but it would still phantom break a few times during a 12 hour trip. But when in full sun, it did brake 10+ times.

Filed Feb 18, 2023 · Acceleration, Brakes · MN

This alert is about "phantom braking", which is well known to Tesla owners, and the subject of much online discussion among owners who seem to all experience this and are furious that it continues to exist. Here's what happens, very, very often yet: with adaptive cruise control engaged (with or without "autopilot", ie 'autosteer' also engaged), the brakes are applied suddenly without any need for braking (no objects in the way of travel, etc). We just completed a trip on I-94 from Billings/Red Lodge, Montana across North Dakota, where phantom braking was experienced probably 50 times, with no other vehicles ahead of us, and on perfectly dry pavement, etc. There had also been very dangerous icy conditions (lots of even "skating rink ice") on the stretch of I-94 in Montana, from Billings into North Dakota. Had the phantom braking occurred on one of the sporadic ice patches further east, it could have easily caused a serious accident, not just been a scary nuisance. In situations with heavy traffic, phantom braking could easily result in rear-end collisions by cars that may be following too close to react before we, the Tesla drivers, override the phantom braking by hitting the accelerator--even that simple maneuver cannot be executed before the car has suddenly decelerated 10-20 mph or more. Some of the phantom braking seems to have been somewhat corrected where we'd first encountered it, on I-394 west of dntn Minneapolis--it doesn't happen as often now as it did a few years ago. There we'd suspected it may have been triggered by the shadows cast on the pavement ahead of us by overhead bridges. But this rash of events across North Dakota this week brought our worst memories and fears back with a vengeance--and with zero theories that could explain it. On a recent online discussion about this issue, there were several pleas for Tesla to give us a "dumb cruise control" option till this gets fixed. Please help foster solutions to this difficult situation! Thank you.

Filed Dec 23, 2022 · Driver assistance · MI · crash

I have reported several comparable incidents that this recent article describes https://www.theguardian.com/technology/2022/dec/22/tesla-crash-full-self-driving-mode-san-francisco?CMP=Share_AndroidApp_Other to Tesla in 2020. Our Model S doesn't have full-autonomy software, and in our case the described "braking for no reason" happen in cruise-control mode, without the (semi) auto-pilot engaged. In one of our incidents the sudden emergency-like braking caused a rear-end collision with the car behind me, it was however light enough that no visible damage was caused to either vehicle. We had paid $5,000 for the (semi) auto-pilot feature when we purchased the vehicle in 2017. I reported these incidents to Tesla (I have the emails and their responses) and after several rejections from Tesla that the issues were not reproducible I asked them to take the vehicle back (trade-in) and remove it from the streets because it was unsafe to drive. I further argued that I can't sell this vehicle to someone with good conscience without letting them know that they should not use cruise control. Tesla never acknowledged an issue and also never took ownership of the problem, we are still driving this vehicle today. I'm available to provide further detail if needed.

Filed Oct 13, 2022 · Driver assistance · TX

Random breaking was prevalent with driving computer 2.5, which recently upgraded to 3.0. The "phantom breaking" is more general and is very dangerous. There have been locations where the vehicle behind me almost wrecked due to my car brakes slamming on out of the blue. I looked up the issue online and found the problem has been happening for years. My wife will not ride in my car now due to the fear of an experience when this phantom breaking accused while she was with me. I am using adaptive cruise less often and not using autopilot. The downside is that the car's efficiency is reduced when not using these "smart" features.

Filed Sep 23, 2022 · Acceleration, Driver assistance · FL

The issue occurred twice over the period of the past two months, both times I was driving on highway with Tesla autopilot enabled ( It is Adaptive Cruise Control), for no apparent reason the car hit the brakes, all vehicles driving behind me had to hit brakes or change lanes to avoid Collision. Both times I created service request with tesla and got no clear answer to why its happening, first time I was told it is because the exit on map was about couple miles from car location so car had to hit brake hard and change lane to make it to exit but car never tried to change lane, it just did hard braking. 2nd time I was told it happened due to wheel alignment not being accurate. After wheel alignment was done I reached out to tesla again but so far they can not confirm or deny if tesla autopilot is safe for me to drive. I was told to use autopilot at my own discretion. Are car manufactures allowed to sell hardware or software without taking responsibility for its safety ?

Filed Jun 16, 2022 · Acceleration, Brakes · MD

Vehicle automatically and unexpectedly applies brakes when using Cruise Control when no other cars are in proximity or approaching. Sometimes braking is light but other times it is a jolt that is extremely starling. Often happens multiple times within minutes. Unpredictable when it will occur. I have taken the vehicle to Tesla 3 times and they say that they know about the problem but their Autopilot is still in Beta and are not actively working on a fix. On 4/28/2022, while on a trip, there were 5 incidents between 9:51am and 1:43pm.

Filed Jun 8, 2022 · Brakes, Driver assistance · MD

On several occasions, I have been doing highway driving, and my 2017 Tesla Model S suddenly brakes without warning. It happens primarily on cruise control and around curves on the highway. On a trip to Atlanta earlier this year, it happened twice. I bought the car used in 2021, and it drives very well, but the unexpected braking at high speeds is scary.

Filed Apr 18, 2022 · Driver assistance · WA

While the tesla “traffic aware” cruise control was engaged (part of the “auto pilot” system), the car breaked aggressively for no good reason. This has happened 4 times over the 9,000 miles I’ve driven the car, always at freeway speeds. Although no injuries or damage resulted so far, serious injury could occur if a car is following me too closely when this happens.

Filed Feb 28, 2022 · Driver assistance · CA

Additional report for same problem with DIFFERENT car. This report is not about a single incident, but rather a REPEATED problem over several years with the adaptive cruise control on 3 different Tesla cars I have owned. These cars are a 2017 Tesla S, and 2 different 2021 Tesla Y models. in each case, whenever these cars are driven on a highway with the adaptive cruise control engaged, several times during each hour of driving, the cars will rapidly brake/decelerate with no action taken to cause the situation by the driver, nor any external situations with the traffic that would justify them. With the Tesla regenerative braking, these deceleration events are so extreme that it would be easy to imagine an accident with a car following closely behind. Indeed, with these situations occurring with no warning and extreme braking they are quite frightening to the passengers traveling in the car. During the most recent occurrence, I noted the exact day and minute of it's occurrence, and filed a service request with the local Tesla office. Even with the exact time of this event, the service center was unable to find anything wrong with the car. The Tesla service center attributed this issue to problems with the Autopilot and Full Self Driving software, but none of my cars have had this optional software-only the software which came standard on each of these cars. While otherwise appreciating the good characteristics of these cars, this unexplainable deceleration problem is what caused me to sell the prior 2 models before purchasing this latest model Y, hoping that this problem would not recur. It is worth noting that I have owned several other make and model cars with comparable adaptive cruise control, yet this situation never occurred even once on any of these other makes of cars.