Chevrolet Bolt EV transmission problems

POWER TRAIN

2027 CHEVROLET BOLT – SUDDEN FORWARD LURCH / PROPULSION EVENT WITH MULTIPLE COMMUNICATION FAULT CODES While driving my new 2027 Chevrolet Bolt, I was stopped at a traffic light. When the light changed, I applied the accelerator gently to move forward. The vehicle suddenly produced a loud bang or clunk and lurched sharply forward. All of the yellow instrument panel lights flashed on for a few seconds. The acceleration was abrupt and substantially different from my accelerator input. Surrounding drivers were alarmed. The event was sufficiently forceful and unexpected that I considered it a safety issue involving propulsion control. I was not accelerating aggressively; this was a gentle acceleration, in traffic, making a left turn onto a freeway ramp. I subsequently brought the vehicle to the Chevrolet dealer for diagnosis. The dealer retrieved the following diagnostic trouble codes: U164B; U164E (5 times); U0485; U11FD; P3013; U1A25; U160A (3 times)l U197A (3 times); U0159; U1126 (2 times); U1150; B1A25; U1607; U1151 Several of the retrieved codes are U-series communication/data-network codes. The vehicle has now been at the dealership for three days; so far the dealer has not provided an explanation for the sudden lurch or identified the underlying cause of the diagnostic codes. Previously the car was at the dealership for 15 days. I am concerned that an intermittent electronic, communication-network, propulsion-control, power-supply, software, or related fault could cause another unexpected propulsion event. The vehicle has also experienced charging/range abnormalities, and code P3013 was among the codes retrieved by the dealer. I do not know whether those issues are related to the lurch event, and I am not asserting that they are. I am reporting them because they may be relevant to NHTSA’s evaluation of the vehicle’s electrical and control systems. I am requesting that this incident be recorded as a potential safety defect

NHTSA complaint #11755494 — an unverified report by a vehicle owner.

POWER TRAIN

When driving the car through a busy intersection there was a sudden, brief surge of acceleration, followed by deceleration and the vehicle cutting all motor power and becoming inoperable. The MIL lamp illuminated and the "Ready" light went out. I was unable to move the vehicle out of traffic until I got out and disconnected / reconnected the 12v battery to reset the car systems. The problem is difficult to reproduce, happening randomly, sometimes with multiple months between incidents. The incidents happen with no warning, and there are no other symptoms associated with the issue. The dealer mechanic indicated it is likely the issue indicated in Chevrolet TSB 19-NA-220, indicating the root cause is the resolver feedback connector on the electric drive unit damaged during vehicle assembly.

NHTSA complaint #11741473 — an unverified report by a vehicle owner.

POWER TRAIN

Recurring electronic transmission shift control failure on a 2023 Chevrolet Bolt EV. The Electronic Transmission Shift Control Pushbutton Circuit Board (GM part designation K212) has failed twice within approximately 9,300 miles. First failure occurred at approximately 45,695 miles in July 2025. The dashboard displayed a malfunction indicator and a "Service Transmission" warning. Diagnostic trouble code U18D2 was set: Lost Communication with Transmission Range Selector Control Module on the Powertrain Sensor CAN Bus. The selling Chevrolet dealer replaced the K212 pushbutton circuit board and reprogrammed the HPCM2 module. Second failure occurred at approximately 54,969 miles in March 2026, only about 9,300 miles after the first repair. Same diagnostic code family, including the identical U18D2 code, plus U0076, U18C6, and U240E. The same dealer replaced the same K212 pushbutton circuit board a second time. The repair was processed under manufacturer warranty. Safety risk: when the failure occurs, communication with the transmission range selector is lost intermittently and without warning, leaving the vehicle unable to be reliably shifted into Drive, Reverse, or Park. This creates a clear hazard in traffic, parking lots, and on inclines. The failure mode is sudden and the warning lamps appear only after the malfunction has begun. The component is located beneath the center cup holder area. There is no visible waterproofing or moisture isolation around the circuit board, despite its location directly under a known liquid exposure zone. The failed component from the second repair was reportedly shipped back to GM by the dealer. The vehicle is available for inspection. The failure has been confirmed twice by an authorized Chevrolet dealer.

NHTSA complaint #11736684 — an unverified report by a vehicle owner.

POWER TRAIN

I started losing Regen braking intermittently, when this happens the brakes themselves don't work well and there's no warning, you lift of the pedal expecting the car to stop and its rolling freely, to push brake and its not stopping like you expect, then it thuds and lunges forward a bit and stops. It was rarely happening, now the car can barely be driven. I have not got it into a shop yet. It throws DTC P182B, P182D, P1840, and U0401 every time. Clearing them, even while still moving brings it all back to normal, except an image of my previous drive will be frozen on infotainment that I have to hard reset to get it to work. Also backup camera does now work when these codes are active. I have found 1 person online that is having this exact issue. It's terrifying to approach a stop light and used to 1 pedal driving and I'm rolling freely instead. the first incident of it was 03/05/26 and has progressively worsened. My code scanner keeps records of when I clear the codes,

NHTSA complaint #11732285 — an unverified report by a vehicle owner.

POWER TRAIN

I was driving on the highway above 60 mph, and I suddenly got a "propulsion power reduced" alert, along with a yellow indicator light. I almost immediately thereafter got a message saying "speed reduced to 50 mph" and then "speed reduced to 30 mph." I got no acceleration when I depressed the accelerator pedal. In fact, it felt like the car had engaged the regenerative braking to actively slow me down. This is a life-threatening safety flaw, as it was difficult to get to the breakdown lane. The only reason there was no collision was that there was relatively light traffic. I managed to get to a breakdown lane and then, after restarting the car, to get off the highway and into a parking lot, where I called for a tow. The car was towed to the dealer I bought it from and, the next day, they inspected the car and determined that the auxiliary transmission fluid pump had failed and needed to be replaced. I've seen many reports on reddit that this part fails on chevy bolts. What makes this truly unsafe is that there was no warning whatsoever that something was wrong. Everything seemed fine (after I got a new battery under the big bolt battery recall) until the car suddenly cut power and slowed me down in the middle of the highway. This car needs to be recalled again.

NHTSA complaint #11710387 — an unverified report by a vehicle owner.

POWER TRAIN

While waiting to turn left at a light and driving in "L" (one pedal) mode, I started to release the break in anticipation of oncoming lanes clearing, as I lifted the pedal the car lurched into the intersection. The Bolt normally accelerates very gently in L mode when no break is applied, but does not lurch forwards like this under normal conditions. The breaks did work, and I was able to stop, but I was now in the middle of the intersection and slightly encroaching into oncoming lanes. I tried to accelerate to pull through, but the car did not respond. After several second of frantically pushing the accelerator, the car slowly and jerkily moved forward and cleared the intersection. My Chevy dealer says this is a known problem with service bulletin "Chevrolet TSB 19-NA-220". In my opinion this is incredibly dangerous and should have been recalled. However, there is no recall that I can find and outrageously Chevy will not cover this manufacturing defect under warranty as they specifically exclude wiring harnesses due to past issues with rodent damage, and they are hiding behind that rule.

NHTSA complaint #11709509 — an unverified report by a vehicle owner.

POWER TRAIN

Vehicle started to surge while driving (both small acceleration forward and large deceleration) without any change in brake or accelerator position. Eventually a "Propulsion Power Reduced" message was presented on the console followed immediately by no forward propulsion (accelerator completely unresponsive) and forced to coast to a stop on the side of the highway. Car refused to shift out of park or neutral following breakdown. Car taken to dealer to troubleshoot and was told that a P0A3F code was present and that the engine harness needed to be replaced in accordance with NHTSA bulletin 19-NA-220. This bulletin calls out that the harness was likely damaged during initial install at factory and the dealer representative confirmed that the pins were damaged as described. Car was given back to drive home after harness was checked (owner decided to explore options before scheduling repair), but broke down due to surging and complete loss of power within 2 miles of dealer. Troubleshooting to confirm harness damage is suspected to have worsen the condition and made un-commanded accel/deceleration followed by complete loss of power likely. Uncertain why this condition would be exempt from recall if OEM is aware of installation issues at factory. Driving with this condition was as bad or worse than other type model loss of power conditions that have been recalled. Recommend at least clarifying that cars confirmed to fall under this bulletin and associated inspection should not be deemed roadworthy until a repair is made.

NHTSA complaint #11706654 — an unverified report by a vehicle owner.

POWER TRAIN

My wife of [XXX] and grandson were driving our Chevrolet Bolt, crossing a busy 4 lane highway when suddenly and w/o any prior warning, the Bolt lost propulsion. Caught blocking 2 of those lanes, she was fortunate that men stopped their trucks and pushed her car up hill and into a church parking lot. She called me and I tried resetting everything to factory settings, and the Bolt seemed okay-for a short time. I hooked a diagnostic unit to the car and found an error code that indicated either the failure of the pre-charge resistor or the HV contactor-both in the battery pack. This was a pack replaced by the dealership back when Bolts were randomly catching fire and destroying themselves and nearby property. Now these packs are failing again and there are service bulletins addressing this fact and that it is common in 2017 and 2018 Bolts. GM however has not sent out warnings to its unfortunate customers warning them of this common failure and life- threatening problem. Luckily today I'm dealing with the Bolts warranty rather than two funerals. All of that took place on 11/22/25. In the hour following the first failure, this situation repeated itself 4 more times. The last time there was no restarting it, or the car would shake if put into drive or reverse. As it was Saturday we had to wait until today 11/24/25 to get it towed to the dealership for $140. This failure will require dropping the battery pack and running three tests, then replacement of the faulty components. This should be under warranty according to our and the dealerships records, but this issue need to hit the national news and all Bolt owners should be sent letters warning of sudden and unpredictable failures. This was life threatening for us and will be for many others. Imagine this happening at interstate speeds in heavy traffic. Lives will be lost. This is the second and more dangerous failure for these horrible vehicles, and GM should at this point replace these or refund every owner. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATI

NHTSA complaint #11701262 — an unverified report by a vehicle owner.

POWER TRAIN

On 4/5/2025 I was driving at 35mph and the steering wheel began to violently shimmy. The vehicle became difficult to steer putting safety at risk. Slowed to 25mph but shimmy did not stop. ABS warning light came on and Stabilitrak warning light came on and warning that steering was being was being automatically reduced. Driving became very difficult. Stopped and had car towed to Chevrolet. Car was diagnosed with broken left and right front axle anticlick washers and metallic debri found on sensors. Both front axle anticlick washers were replaced, sensors cleaned, and codes cleared, and brake fluid had to be flushed. Cost $850 to repair. Subsequently found out another friend had same thing happen to their 2018 Bolt. This was a safety issue and put us at risk while driving.

NHTSA complaint #11667654 — an unverified report by a vehicle owner.

POWER TRAIN

The vehicle was driving and lost all power and came to a stop. After about 5 seconds vehicle regained power. The "check engine light" illuminated on the dash. took to dealer and stated could not replicate problem. Only have the report from vehicle computer and the EV technician did not understand the information and had to call GM for help. Got car back and problem happen again. Dealer had GM specialist out to help. GM reset computer and problem just happens again.

NHTSA complaint #11636983 — an unverified report by a vehicle owner.

POWER TRAIN

While traveling at highway speeds, my Chevrolet Bolt (2020 with 20K miles) made a clunking noise followed by a loss of speed. The clunking noise had previously been reported to the dealer, but they were not able to identify any issues at the time. During this incident, however, the car ultimately lost all speed, forcing me to pull over to the side of the highway. This sudden loss of propulsion posed a significant risk to my safety and the safety of other motorists, not only due to the loss of power, but because it happened at an interchange where multiple highways are connecting. I was left on the side of the road waiting for a tow because the car was inoperable. Prior to this sudden failure, there were no warning lamps, messages, or other symptoms, aside from the previously reported clunking noise. After this incident, the dealer diagnosed the issue as the one listed in the technical service bulletin, which states that "the terminals may not have been perfectly aligned during installation at the vehicle assembly plant." Unfortunately, this issue was not covered under the warranty and currently this problem is not a recall item for the Chevrolet Bolt.

NHTSA complaint #11632822 — an unverified report by a vehicle owner.

POWER TRAIN

While at a remote location, I unlocked and entered the vehicle normally. When I tried to start the vehicle, numerous unrelated error messages appeared on-screen. The instrument panel was energized, but the vehicle could only shift into neutral and park. Power steering was lost, as was window functionality. The vehicle could not be fully started, nor could not it be fully shut off either. It was stuck in a peculiar, unsafe, and unresolvable state of energized limbo. AAA towed the car to Watson Chevrolet who determined that the 12v system (vs propulsion) battery malfunctioned and needed to be replaced. There is no information in the owner’s manual about this issue. The tow truck mechanic had no clue what was wrong. Fortunately, we were in a safe location. But under different circumstances, such as being roadside, this could have been a very unsafe situation. This is the original battery. The car was recently serviced and there was no indication the battery was failing. This problem was only an annoyance for us, but it could have been much much worse under less favorable circumstances.

NHTSA complaint #11608511 — an unverified report by a vehicle owner.

POWER TRAIN

Car stalled suddenly on road. Can’t change to any driving gear, only neutral. Towed to dealer, diagnose indicated wiring harness was the cause. Expensive fix for ~$400 part with ~$3200 labor cost in addition to dangerous sudden stall.

NHTSA complaint #11589044 — an unverified report by a vehicle owner.

POWER TRAIN

The engine compartment wiring harness Part Number: 42765196 wiring shorted out due to the chaffing of wires in the harness. The dealer is replacing the harness but there is no known changes that will prevent this in the future. $3,000 repair bill. I have asked for the defective harness to be returned to me for examination. This is a major safety concern as in my case, the Chevrolet Bolt would not move either in forward or reverse (Note: the other electrical systems and battery continue to work. This failure happen in rush hour traffic and the vehicle was nearly hit by passing cars. There was no warning that the propulsion would entirely shut down. The dealer reported that they had seen this problem before. No one from the manufacturer are interested in this. A check engine light had come on the night before and I had set up an appointment with the dealer for the next day and add reported the vehicles' issues that I had observed. There is no warning to indicate that the problem would result in the complete loss of propulsion.  

NHTSA complaint #11587057 — an unverified report by a vehicle owner.

POWER TRAIN

While approaching a stop light, the car experienced a loss of propulsion and gave me an error message about it. The car told me to pull over as soon as possible, however, in busy morning traffic, this was impossible. Even if I'd had space to pull over, the car came to a stop and locked up with the error message "Conditions Not Right For Shift." It had to be rebooted several times before it could be shifted into neutral long enough to be pushed to safety. From there, it then had to undergo a hard reboot to return to a state where it could be shifted into Drive. A dealership service center confirmed the problem under as described under service bulletin 19-NA-220. There were no warning lamps or other symptoms of the problem. The car is available for inspection upon request.

NHTSA complaint #11579963 — an unverified report by a vehicle owner.

POWER TRAIN

Vehicle stopped while driving down the road lost power threw up multiple codes and was stuck in the middle of the roadway!

NHTSA complaint #11548160 — an unverified report by a vehicle owner.

POWER TRAIN

While waiting to make a left turn, the car lurched forward about a foot and went into park.It would not shift into any gear. A warning briefly showed up on drivers display which said DO NOT SHIFT UNTIL ???? RESETS. I turned car off but it immediately came back on automatically, and for twenty minutes I was in the intersection blocking traffic (police called to protect me from traffic). On drivers display a car symbol with exclamation point through the car was showing. After twenty minutes I turned it off again and it stayed off until I turned it on. The display of car with exclamation point was still showing. I could then shift into another gear and drive home less than a mile. When I checked car later car with exclamation point display was gone. Everything seemed. I was driving in one pedal mode.

NHTSA complaint #11543576 — an unverified report by a vehicle owner.