Service brake booster emits a semi continuous tapping/clicking noise. Chevrolet state that it is not a safety issue and does not require repair. However, it is difficult to have confidence in the braking system while this sound persists and it is a constant distraction while driving. Plus, the ability to sell or trade the vehicle in this condition is diminished. Elimination of the noise involves costly removal and replacement of the brake booster assy. Chevrolet fixed an apparently identical issue on the bolt model with a software update, but currently have no intention to do anything similar for the Volt model.

- Everett, WA, USA

My 2017 Chevy Volt has been making a clicking noise coming from the brake booster assembly since I have bought it. When your foot is released from the brake pedal, there is an audible click (3-4 times a second) inside of the cabin and I've decided to make a formal complaint as GM isn't taking the appropriate action to fix this issue. My reasoning is that this issue is not only common on the Chevy Volt, but also the Chevy Bolt as they share the exact same brake booster. For the Volt, dealers are instructed to replace the Brake Pedal Retainer - GM (39081933) and the Brake Master Cylinder - GM (84006919). This repair is often quoted in excess of $2,000 even though there is a very high likelihood of the issue returning even when the parts are replaced. For the Chevy Bolt, dealers were instructed to stop replacing the brake booster as they determined there was a software fix that could solve the issue. There was a TSB regarding this which details both the problem and the repair procedure (# [XXX]) [XXX] While GM fixed this issue on the Bolts, the Volts have the exact same issue and owners are being directed to spend $2,000+ to make a repair that won't even fix the issue. GM needs to release the software fix for the Volts so that the issue can be resolved properly. This burdens current Volt owners improperly, as GM has proven that a software release can fix this but has thus far refused to address and implement it. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

- Rochester, NY, USA

BECM failure resulted in a situation where the vehicle drove with erratic surging power delivery throwing engine codes P1E00, U2603, U2604, U2605, U2606 Regen braking in this vehicle has a dedicated control on the steering wheel which applies only regen braking no friction brakes. When battery state of charge is high this can result in a situation where the regen braking button abruptly (i.e. during one extended activation of the button) delivers less brake force than the user is demanding.

- Pflugerville, TX, USA

Several times since I purchased the car in Jan 2022, the left and/or right front brakes have dragged without brake pedal actuation while I was driving in surface street traffic, typically with speed limits of 25 to 35 mph. This has resulted in overheating of the brake caliper, rotor, and wheel. Typically the car can be driven again without issue after two hours of cool-off time. This phenomenon has occurred during both battery/electric and gasoline engine operation of the plug-in hybrid car. There are no instrument indications of a brake malfunction when it happens. It first becomes perceptible as a pulsation through the steering wheel and requires increased throttle pedal pressure to maintain speed. I brought the car to my local Chevrolet dealer after the first two of these incidents. Their first recommendation was a new set of tires to remove the influence of one mismatched tire. The new tires did not resolve the issue, and the dealer has not performed any other corrective action beyond a recommendation to replace calipers and rotors. Due to the intermittent nature of the failure and the fact that it affects both of the front brakes, I believe this is an ABS system issue and not a caliper/rotor issue, and I have not replaced those parts yet. The car's adaptive cruise control does not work properly. It almost always fails to set and shows "Adaptive Cruise Temporarily Unavailable" regardless of road conditions. This condition is intermittent and is not reproducible on demand. This condition is dangerous because it overheats the brake, wheel, and steering components. The heat may have damaged the wheel bearing, steering components, and CV joints. The heat also creates a risk of sudden wheel and/or tire failure while driving. The unexpected application of the brakes affects vehicle response to throttle and steering inputs, and has the potential to reduce driver control of the vehicle.

- Riverside, IL, USA

I was driving on the highway at speeds greater than 60mph. Traffic came to a sudden stop and the pre-crash avoidance assisted with breaking. I resumed driving. The front right tire began smoking. I pulled over, the break was locked up and the rotor and pad were damaged. Overnight it releases. I take to service center and they are unable to replicate issue. I had to replace pads and rotors. A month later it locked up again, this time while driving. I became wary of the sighs now and pulled over immediately. Had the vehicle towed to service center. Again, they are unable to determine issue. They said there are no fault codes and no physical issues with breaking system. It is unfortunate the dealer does not know how to repair cars with complex computer operated systems. I don-??t know what to do, right now we are in the stage of replacing random components to see if it fixes the issue. I can-??t keep throwing money at this. I hope you can apply pressure to Chevy to help. I don-??t know what to do, all I know is this isn-??t safe. They had a similar recall for 2018 model year volts breaks locking up. But no recall issued for 2017 model year.

- Raleigh, NC, USA

Late 2021 I noticed a strange noise and a slight stutter in my breaks that would only happen at the end of the breaking motion just before the car would completely stop. The sound and stutter, felt as though a clutch was trying to engaged. I scheduled a service appointment in January to have my tire replaced and car checked. The stabilitrack light came on while I was on vacation and also asked the dealership to check the stabilitrack. The dealership replaced my tires and inspected my car, but found nothing wrong with it. The tested the car and it appeared to be working just fine. I drove around another couple months with no incident. And then the notice and stutter came back, however it was intermittent. The stutter and noise slowly got worse and worse, but stilled continued to be an intermittent issue. On August 1st, while driving to work, my breaks completely failed and I almost got into an accident. I was pulling away from a red that just turned green. There was a red light ahead, I barely got up to 30-35mph before I started cruising towards the light. Started to press down on the breaks to stop and the pedal went straight to the floorboard with resistance and the breaks did not engage. I pumped the breaks frantically several times, with no change and quickly swerved and made a last minute right turn to avoid traffic. I continued to pump the breaks until it eventually did engage. I took the car to the dealership to have it serviced and inspected again, and was told it was the master cylinder that had failed. After it got replaced it was about another 2 weeks before I started to experience a similar issue again.

- Orlando, FL, USA

While using one pedal driving the brake lights do not engage unless brake pedal is used. This is a known issue by the company and was fixed in later models due to it being a problem. After speaking to the company I was advised to go to the dealer who informed me that the company has not offered any sort of update or repair option. If it was not deemed an issue why then did the company fix the issue in later models of the same vehicle" I have had many instances of very close calls with other vehicles. I truly believe if the company didn't believe it was an issue why then was it changed"

- Egg Harbor Township, NJ, USA

On 2 difference occasions over the past 3 weeks, my car has malfunctioned while I was driving. There were no warning lamps, messages or other symptoms prior to this. All of the lights on the dash came on, the power steering went out, the brakes would not work properly and I could not accelerate. I had my child in the car and we narrowly avoided being hit by other cars both times since I couldn't control the vehicle. I couldn't even power the car down initially but was finally able to turn it off and back on and function resumed after several cycles. I was driving on electric battery that time. The first time, the dealership stated that the following codes were present: P1e00 and P16BA. They replaced the g1 a/c compressor. The incident occurred again a week later when I was driving on gas. At that time, there were history U codes present for every module, per the technician but no current codes to identify the problem. The problem has not been able to be reproduced since. The 2nd incident occurred out of state and my car was towed back to Texas where I live. The dealership there refused to investigate the incidents since they couldn't reproduce them and there were no current codes showing. It has subsequently been towed to a different dealership where they are still trying to identify the issue. I contacted General Motors and was contacted by a rep who escalated the issue. The next rep escalated it again greater than 48 hours ago and I have received no further contact from GM. The 2nd rep informed me that since the dealership that it was originally at says that it's safe to drive that they can't do anything. This car is NOT safe to drive.

- Garland, TX, USA

When I put the car in park the vehicle tells me I need to shift to park even though it is shift to park. Vehicle will not shut down and drain itself.

- Highland, IN, USA

This vehicle has a -??Shift to Park-?? issue which is well established all over the internet. I-??m afraid to walk away from the vehicle when that message pops up. Seems to be something that could injure/kill someone if the car cannot be left in park safely. This has been an ongoing/intermittent issue for months. The date stated below only represents today-??s date of report.

- Upland, CA, USA

It is an ongoing issue and that happens intermittently. When arriving to a stop (at times) the car still advances forward about a foot, even when the brake pedal is being used as far as it can. Also the vehicle claims to be losing propulsion, often, and seems strained when operating when the message appears.

- Selma, CA, USA

I exited the vehicle and it rolled backward. I was struck by the door and crushed between the car and an adjacent brick wall.

- Flower Mound, TX, USA

We own two 2017 Chevy Volts. Both have two issues: 1) often cruise control does always stay engaged due to brake pedal slipping to a very slight depressed position. 2) shift-to-park- cars will not properly go into park sometimes and thus cannot be turned off. These two issues are clearly manufacturer defects as both cars were bought new and within a month of each other. I will enter this for my other VIN number as well. These have been ongoing issues that we are having to spend money to correct and there are many reports of these being issues, yet there is no recall. We purchased both cars brand new within a month of each other. Both issues have been ongoing and have occured more than once.

- Greenville, SC, USA

Purchased a 2107 Volt premier with 40K miles in July 2020. My wife was driving the car and it lost power on the freeway with a "shift to park" warning and check engine light. She was able to glide over to the shoulder and I came to rescue her. After repeated on off cycles I got the car to move a couple of miles with several "jerking" motions while driving then it died again and I lost power braking (went to manual only). This time I was unable to "re-boot it" and had onstar have it towed to a local Chevy dealer who has a "certified ev specialist"

- Imperial Beach, CA, USA

While driving on city streets and highways, the adaptive cruise control will not engage 25% of the time and will disengage without notice. "adaptive cruise control will appear in dic. However, this creates a safety hazard as you never know if the car will automatically slow down. I have filed case # 9-5379585813 with Chevrolet and been to four dealers and they refuse to fix the problem. They no longer return my calls. I am afraid to use the cruise control.

- San Antonio, TX, USA

After diagnosing an audible tick/click sound that occurs whether the car is powered on or off but stops momentarily when the brake pedal is applied, I was told the electric brake booster is bad and must be replaced. But GM has no parts available. I was told to drive the car and if the part fails completely, I will have no brakes at all. It has been over 3 weeks and there is no eta on parts.

- Inman, SC, USA

When approaching a stop and applying the brake pedal, the brake pedal suddenly sinks and car loses traction and the car suddenly feels like it starts to slide. After releasing and then reapplying the brakes, the returns to normal.

- San Pedro, CA, USA

Adaptive cruise control unavailable randomly occurs while driving using adaptive cruise control. Presents a large danger of hitting other vehicles if the adaptive cruise control is used to come to a complete stop as it will randomly disengage while coming to a stop. Cruise control only works 4/10 times attempted and was "fixed" by the dealer with less than 500 miles on the odometer. However the problem recurred within a day. Looked it up in forums and it is not an uncommon problem. Holding foot under the brake pedal allows cruise control to work but is more dangerous than randomly cutting off. No one in Volt forum has gotten a complete fix to date. When they do I will be getting mine repaired armed with the correct information. But it is dangerous.

- Laurel, DE, USA

While approaching a red light at 35mph on a smooth road when I pressed my brake pedal nothing happened for nearly a second then the brakes worked as usual. Luckily no one was in front of me or I could of easily been in a crash. The Volt has a brake-by-wire system with regenerative braking. I feel that either the regenerative braking failed and the computer took a long time to revert to the friction brakes or the brake module temporary failed and neither regen or friction brakes were available. I've driven a first year leaf where sometimes there is a slight delay when switching to friction brakes in certain situations, and this event was much much worse than that. Road and weather conditions were perfect that day.

- Cedar Park, TX, USA

The brake pedal and gas pedal both modulate pressure needed to either accelerate or brake. The brake pedal will change pressure needed to brake suddenly, causing you to apply much more force to brake pedal, which is unexpected and dangerous. For example, when driving at highway speed, a car in front of you stops, and you apply brakes. Traffic clears and you release brakes, but then car in front stops again and requires you to brake again suddenly. This time the brake pedal will require more pressure and pedal travel is significantly more. This is unsafe and needs to be changed.

- San Antonio, TX, USA