2017 CHEVROLET BOLT EV Service Brakes Problems

On August 17th, 2025, my wife was driving our 2017 Chevrolet Bolt EV at low speed, pulling into a parking spot. The vehicle suddenly accelerated forward with enough force to cause significant damage to a fixed barrier. She does not recall pressing the accelerator at that moment. The degree of acceleration was disproportionate for a brief accidental press. Immediately after impact, smoke or dust was visible rising through the center console area. No airbags deployed, but it appeared similar to smoke from pyrotechnic devices. My wife sustained seatbelt-related bruising across the chest and thighs. The vehicle remains drivable. I have included photos detailing damage to the car and the fixed barrier. We are aware of the GM accessory all-weather floor liner recall (21E-089), but are not certain if our vehicle’s liner was part of that campaign. We are reporting this incident to ensure there is a record in case this reflects unintended acceleration or another defect.

This tends to only happen below 74 degrees Fahrenheit and happens excessively between 72 and 74 degrees Fahrenheit. While driving with one pedal engaged (labeled as low on the shifter since they re-used another model's shifter for the first several years of the Bolt EV), the cruise control will randomly disengage and force the vehicle to immediately slam on the brakes. Usually its not a big deal, but when it happens at highway speed as you're just passing a semi or large vehicle and merging back into the lane in front of it, it becomes dangerous very quickly, which has happened a couple of times now. I would venture a guess that its not related to the cruise control directly, but some system that its relying on is forcing it to deactivate the cruise control. The only other issue this vehicle is having that might be related is that the blind spot detection system is not working correctly on the left side. I know there's a TSB for the aluminum Butyl tape becoming damaged or missing, but if that's causing my car to slam on its brakes in front of fully loaded semis, Chevy should probably be persuaded into re-coding how their cruise control gets disengaged. Especially since this blind spot detection system issue seems somewhat common. Either way, something is causing my car to randomly slam on its brakes in the middle of the highway and Chevy says there's nothing they can do about it because its not setting a code. This is definitely a dangerous safety issue that they should be forced into actually diagnosing more than just plugging a computer in and saying: "whelp, nothing to see here." and returning it to the customer with a "we can't do anything, sorry."

In Sept 2020, GM issued Service Bulletin 20-NA-170 regarding rapid popping or clicking noises coming from the I-Booster hardware under the hood in the braking system. Earlier fixes for this issue involved replacing the I-Booster hardware, but that didn't solve the problem. The new fix called for a software update to the Brake Booster Control Module. The Bulletin states: "Correction -- DO NOT replace the I-booster assembly. Update the Brake Booster Control Module with the latest software." I reported this brake/electrical system issue to NHTSA on April 24, 2022 (# 11461966) and January 25, 2023 (# 11503678), and have had no response or investigation by NHTSA regarding the hazard of this software defect. When the hardware eventually fails--and it will due to 1000's of unnecessary use cycles--what happens to the braking system?

1. Steering, the steering gear does not return wheels to straight position when exiting a turn, I need to forcefully move steering wheel from a turn back to a straight position. 2. Brakes, after hitting brake a knocking sound is heard. Also does this when car is off and opening and closing doors, was told this is a brake actuator problem.

In Sept 2020, GM issued Service Bulletin 20-NA-170 regarding rapid popping or clicking noises coming from the I-Booster hardware under the hood in the BOLT braking system. Earlier fixes for this issue involved replacing the I-Booster hardware, but that didn't solve the problem. The new fix called for a software update to the Brake Booster Control Module. The Bulletin states: "Correction -- DO NOT replace the I-booster assembly. Update the Brake Booster Control Module with the latest software." What happens to the brake system if the software update is not applied? Does the I-Booster hardware eventually fail because of the 1000's of unnecessary use cycles, and then what happens? Why hasn't a recall been issued for this possible safety issue caused by a software defect?

Exact details UNKNOWN. Description: About 2 yrs ago, releasing the brake pedal started triggering rapid popping sounds from engine compartment. The popping sounds are rapid--maybe 4 or 5 per second--and continue for a few seconds or more, up to at least 30 seconds depending on ambient temperature and main battery charge level. Opening the driver side door following vehicle at rest can also trigger this popping noise. But mostly the popping occurs when brake pedal is fully released during operation of the vehicle. GM responded initially to reports of this issue by replacing brake control parts; but more recently, according to a service bulletin (see uploaded document), a software update may be used to fix the problem. Since many vehicles which have the problem are out-of-warranty, GM charges owners for applying this software update. How can we be sure that this issue is not safety-related? If this is a software defect in the braking control system, why is warranty coverage required for the update?

When using mechanical brakes the iBooster makes a knocking noise. Every time the brake pedal is used the noise appears. This is concerning as I'm afraid it may impair the brake faction and potentially create a danger on the road. So far dealers are unwilling to help.

Parking button may not fully engage when pressed causing vehicle to roll forward in drive gear or while in reverse causing vehicle to collide. Vehicle will automatically go into park when driver door is opened, but button can take deep press to fully engage into park. If driver removes foot from brake petal before vehicle is in Park car moves.

There is an intermittent RAPID TAPPING NOISE COMING FROM THE BRAKE BOOSTER upon opening a door, or releasing the brake pedal (standing still or while in motion), or unplugging the power cord. The behavior is more frequent on colder days. This tapping noise typically continues for nearly a minute. Tapping the brake pedal causes the noise to cease momentarily. Very slight movement on the brake pedal can sometimes stop the tapping. This behavior began more than a year ago. I took the car to the Chevrolet dealer and was told a firmware update would be provided in Q1 2021. I am concerned the behavior may be an early warning sign of brake system failure, which could occur while driving.

THERE IS A RAPID TAPPING NOISE COMING FROM THE BRAKE BOOSTER UPON OPENING THE DOOR. TAPPING THE BRAKES WILL MAKE THE NOISE STOP. FOR A FEW WEEKS THIS WOULD STOP THE NOISE UNTIL THE NEXT OCCURRENCE AFTER SITTING FOR HOURS. IT HAS PROGRESSED SO THAT THE TAPPING WILL RETURN AS SOON AS THE BRAKE PEDAL IS RELEASED AND CONTINUE WHILE DRIVING. UPON PARKING, THE NOISE WILL PERSIST FOR UP TO A COUPLE OF MINUTES AND THEN STOP. PROBLEM CONTINUES. I TRIED TO ATTACH AN AUDIO FILE BUT IT WASN'T ACCEPTED AS AN APPROVED FILE.

Mileage: 12,000

BRAKES STARTED MAKING NOISE AT 27,000 MILES . WE DRIVE IN L MODE NEVER TOUCH THE BRAKES. DEALERSHIP SAID METAL TO METAL ON ALL 4 WHEELS. I SAID THAT'S IMPOSSIBLE WE DON'T USE THE BRAKES . THEY WOULDN'T CONSIDER A WARRANTY PROBLEM. RAPED ME FOR NEW BRAKES. $800.

Mileage: 27,000

THERE IS A RAPID TAPPING NOISE COMING FROM THE BRAKE BOOSTER UPON OPENING THE DOOR OR HATCH. TAPPING THE BRAKES WILL MAKE THE NOISE STOP. FOR A FEW WEEKS THIS WOULD STOP THE NOISE UNTIL THE NEXT OCCURRENCE AFTER SITTING FOR HOURS. IT HAS PROGRESSED SO THAT THE TAPPING WILL RETURN AS SOON AS THE BRAKE PEDAL IS RELEASED AND CONTINUE WHILE DRIVING. UPON PARKING, THE NOISE WILL PERSIST FOR UP TO A COUPLE OF MINUTES AND THEN STOP. PROBLEM CONTINUES TO THIS DAY (3 MARCH 2021) N.B. IT WOULD BE NICE IF ONE COULD UPLOAD AN MP3 OF THE SOUND. THANK YOU!

Mileage: 44,500

THERE ARE CONSTANT STRONG KNOCKS 8 TIMES PER SECOND IN IBOOSTER. KNOCKS ARE HEARD IN THE CABIN AND UNDER THE HOOD. DISAPPEAR ONLY WHEN YOU PRESS THE TOMOZ PEDAL.

Mileage: 41,000

UNLESS THE BRAKE PEDAL IS DEPRESSED THERE IS A RAPID TICKING NOISE COMING FROM THE MASTER BRAKE CYLINDER UPON OPENING THE DOOR, EVEN WITHOUT ENGAGING THE START BUTTON. THIS SOUND CONTINUES WHETHER THE CAR IS STATIONARY OR MOVING UNDER ALL TRAVELING OR STATIONARY CONDITIONS UNLESS THE BRAKE PEDAL IS DEPRESSED SLIGHTLY. WE FIRST BECAME AWARE, REALLY NOTICEABLE, ABOUT IT UPON OPENING THE CAR DOOR IN JULY, 2020.

Mileage: 24,000

INSTALLED CHEVROLET PREMIUM ALL-WEATHER FLOOR LINERS P/N: 42686568. WHILE PASSING ON THE HIGHWAY, THE ACCELERATOR PEDAL BECAME STUCK AT FULL THROTTLE UNDER THE LINER. UNABLE TO SHIFT TO NEUTRAL AND WITH MINIMAL SLOWING FROM PRESSING THE BRAKES, I HAD TO REACH DOWN AND TUG ON THE MAT UNTIL IT DISLODGED FROM THE PEDAL. I GOT OFF THE HIGHWAY AND EXAMINED THE LINER FINDING THAT ONE OF THE SECURING CLIPS HAD COME UNATTACHED (LIKELY FROM TUGGING ON IT). I REATTACHED AND VERIFIED CORRECT MAT INSTALLATION. LATER WHILE PASSING ANOTHER VEHICLE ON THE HIGHWAY THE ACCELERATOR BECAME STUCK AGAIN CAUSING UNCONTROLLED ACCELERATION. EXAMINING THE MAT AFTERWARDS, THE SECURING CLIPS WERE STILL ATTACHED CORRECTLY. ADDITIONAL INFORMATION: THE CLIPS THAT SECURE THE FLOOR MAT/LINER ARE ONLY ATTACHED TO THE VEHICLE CARPET AND NOT RIGIDLY AFFIXED. WHEN CORRECTLY INSTALLED THE LIP OF THE LINER RISES UP AND ENDS WITH ALMOST NO CLEARANCE TO THE GAS PEDAL, THEN WITH ONLY A SLIGHT MOVEMENT OF THE LINER IT CAN ENTRAP THE ACCELERATOR PEDAL. OVER TIME WITH FORWARD FOOT PRESSURE ON THE LINER, THERE IS JUST ENOUGH MOVEMENT IN THE LINER AND CLIPS TO ALLOW IT TO SHIFT SLIGHTLY FORWARD AND TO THE RIGHT CAUSING AN INTERFERENCE FIT WITH THE ACCELERATOR PEDAL. IT APPEARS THAT WHEN BOTH THE ACCELERATOR AND BRAKE PEDALS ARE PRESSED AT THE SAME TIME, THE POWER TO THE ELECTRIC MOTOR CONTINUES TO BE APPLIED. TESTING THIS AFTERWARD SHOWED THAT WITH A FOOT ON BOTH PEDALS, THE ELECTRIC POWER METER STILL SHOWED POWER BEING APPLIED AND THE VEHICLE BRAKING PERFORMANCE WAS SEVERELY DIMINISHED. DURING AN EMERGENCY, A QUICK FLICK OF THE SHIFTER FROM DRIVE TO NEUTRAL DOES NOT WORK. THE SHIFTER MUST BE HELD FOR A LONGER DURATION, WHICH IS NOT INTUITIVE WHEN THE VEHICLE IS ACCELERATING UNCONTROLLABLY AND BOTH HANDS ARE ON THE WHEEL.

Mileage: 46,000

18K MILES IN, 1 WHEEL IS GETTING VERY HOT. DEALER CANNOT FIND ANYTHING WRONG. HAS NEVER MENTIONED IT BEFORE, BUT SAYS THEY RECOMMEND REGULAR CALIPER SLIDE PIN CLEANING AND LUBING. WANTS $200. IF IT'S A BAD CALIPER, THEN IT SHOULD BE COVERED UNDER WARRANTY. THEY WILL DO NOTHING. SO I HAVE AT LEAST 1 NON-FUNCTIONAL BRAKE AT 18K MILES. SOUNDS LIKE A SAFETY HAZARD.

Mileage: 18,000

CHEVROLET BOLT HAS "L" DRIVING MODE, DURING WHICH THE CAR WILL STOP IF THE ACCELERATOR PEDAL IS NOT PRESSED. HOWEVER, THE REAR LIGHT DOES NOT RELIABLY TURN ON. IF THE CAR IS AT LOW SPEED, OR IF THE CAR IS STOPPED, THE REAR BRAKE LIGHT MAY BE OFF. THIS INCREASES THE CHANGE OF REAR COLLISION. WHEN IN "L" MODE, THE BREAK LIGHT SHOULD BE ON AT ALL TIMES WHILE THE ACCELERATOR IS DEPRESSED.

ON A SOMEWHAT CROWDED FREEWAY ON RAMP, STARTED TO ACCELERATE WHEN CARS AHEAD STOPPED. FULLY DEPRESSING THE BRAKE PEDAL DID NOT APPLY MAXIMUM BRAKING POWER. THE CAR SLOWED BUT DID NOT STOP BEFORE COLLIDING WITH THE CAR IN FRONT, DESPITE THE FACT THAT THERE WAS PLENTY OF ROOM BETWEEN US FOR THE SPEED WE WERE GOING. LATER EXPERIMENTS SHOWED THAT APPLYING THE LEFT HAND BRAKE CONTROL TOGETHER WITH THE BRAKE PEDAL APPLIED SIGNIFICANTLY MORE BRAKING POWER AND WOULD HAVE STOPPED THE CAR WELL SHORT OF THE COLLISION. FULLY DEPRESSING THE BRAKE PEDAL SHOULD APPLY MAXIMUM BRAKING POWER, AND THE HAND BRAKE CONTROL SHOULD NOT BE NEEDED TO STOP THE CAR AS QUICKLY AS POSSIBLE IN AN EMERGENCY SITUATION. I CONSIDER THIS A SAFETY ISSUE, FOR ALL DRIVERS WHOSE INSTINCT IS TO PRESS FULLY ON THE PEDAL, BUT MORE IMPORTANTLY FOR ANY DRIVER WHO CANNOT USE THE LEFT HAND BRAKE DUE TO A DISABILITY THAT OTHERWISE WOULD NOT IMPAIR THEIR ABILITY TO DRIVE.

Mileage: 620

2017 CHEVROLET BOLT. CONSUMER WRITES IN REGARDS TO REGENERATION DURING BRAKING FEATURE. *LD *JS

3 TIMES IN THE FIRST1500 MILES SMALL STONES HAVE BECOME LODGED IN THE BREAKING, IN BOTH FRONT WHEELS AND NEVER I THE BACK WHEELS. THERE IS A DESIGN DEFECT THAT ALLOWS STONES TO ENTER BETWEEN THE BACKING PLATE AND THE ROTOR. THE BECOME STUCK (LODGED) THERE AND, IN ADDITION TO CREATING A LOUD SCREECHING NOISE, COULD IMPAIR BRAKING AND STEERING, CREATING A SAFETY HAZARD. ALL THIS HAPPENS WHEN THE CAR IS MOVING.

Mileage: 1,000

TL* THE CONTACT OWNS A 2017 CHEVROLET BOLT. WHILE OPERATING THE VEHICLE, A LOUD HOWLING TYPE NOISE WAS PRESENT COMING FROM THE FRONT END OF THE VEHICLE. THE VEHICLE WAS TAKEN TO THE DEALER (BANKS CHEVROLET IN CONCORD, NH) WHO DISCOVERED THAT SMALL STONES HAD BECOME STUCK INTO THE BRAKING SYSTEM BETWEEN THE BACKING PLATE AND THE ROTOR. THE STONES WERE REMOVED AND THE FAILURE WAS REMEDIED, BUT THE FAILURE RECURRED ON THREE SEPARATE OCCASIONS ON BOTH THE FRONT DRIVER AND PASSENGER SIDE BRAKES. THE MANUFACTURER WAS NOTIFIED OF THE FAILURE. THE FAILURE MILEAGE WAS 1,500. *BF UPDATED 8/2/18*JB

Mileage: 1,500