Vehicle over-revs in cold weather. Engine runs excessively fast (4250 RPM) at highway speeds and around 3000 RPM when just sitting. Often times if I pull over and restart the car it will correct itself. This results in MPG as low as 22. The internet is full of examples of people with the exact same problem. I have seen no examples of the problem being solved. The engine will operate correctly in warmer weather (above 50? F). I believe it is related to an aging propulsion battery and could be solved by improved programing to accommodate the battery state.

- Hugo, MN, USA

7/6/2024 Was driving 45 mph on a busy road (running only on the gas engine of this plug-in hybrid). Propulsion Power Reduced message showed near the speedometer. My speed was immediately decreased. The check engine light also came on. Despite pressing the gas pedal, the speed could not be maintained and I had to pull off quickly before causing an accident. Luckily, no accident occurred but I fear would could have happened if I wasn't in the right place to pull over quickly. After getting the car towed to a Chevy dealership, they diagnosed the problem as being with the hybrid battery - it needs to be replaced. I don't understand why I had a full tank of gas, was running on gas, and that a bad EV battery would cause ALL propulsion to stop so quickly.

- Tulsa, OK, USA

Vehicle propolusion reduced and engine not available messages were suddenly showing. Check engine light turned on. Suddenly Stalled/stopped in the middle of highway. Safety concerns

- Bakersfield, CA, USA

I'm constantly receiving a "Propulsion Power Loss" notification on my car. I have brought the car in to a Chevrolet dealer and they refuse to fix it unless I start paying out of pocket costs because the ticket is "closed". This has been going on for about a year since I purchased the car last November and I'm terrified to drive this car since it literally looses power.

- El Cajon , CA, USA

The contact owns a 2012 Chevrolet Volt. The contact stated that while his son was driving 55 MPH, the vehicle lost motive power. The vehicle was taken to the dealer and diagnosed with engine software failure. The contact was informed that the engine software needed to be updated. The vehicle was not repaired and remained at the dealer. The manufacturer was made aware of the failure. The failure mileage was approximately 113,000.

- Bethesda, MD, USA

Car suddenly entersinto a no start and stall.this is being repaired by H&H Chevrolet in omaha at owners expense.the problem seems to be in a faulty batterycharge sensor. The part is being ordered by H&H service department andis notyet installed.as of 2/9/2022.

- Omaha, NE, USA

My car has had ongoing problems with power propulsion, electrical system, and start-up since new and several items were replaced in 2017. I purchased 6 year / 100,000 extended warranty when new. Several items have been replaced. But updates are needed to keep the car running properly. Now the warranty has expired but the vehicle still needs updates to run properly and the dealer wants paid to install updates. This is a scam if the car wont run with out being updated yearly. I have a video of the car in 2017 when I started it up and it sounded as though it was going to blow up. I couldn't shut it off and called onstar to shut off the vehicle. That is when several items were replaced. The car is in the dealership again for another update. 8-28-20. There was an updated performed 11-11-19 and 10-10-18. It seems as though there is always an update being performed.

- Farmland, IN, USA

I was driving the car normally in electric mode, and parked it with one mile remaining of electricity. Upon restarting the car a few minutes later, the gasoline engine came on and was revving at a very high rate. In addition, a pop-up message on the dashboard read 'propulsion power is reduced.' The engine continued to rev high and I was only able to achieve a speed of about 30 mph during my two-mile ride home. Upon parking the car in garage and charging it, the problem disappeared. It was 90 degrees outside when this happened.

- Lakewood, CO, USA

The contact owns a 2012 Chevrolet Volt. The contact stated that while driving at 60 mph, the reduced propulsion error message was displayed on the instrument panel. The engine revved up and the vehicle stalled without warning. The contact pulled over and restarted the vehicle however, the vehicle failed to accelerate. The vehicle was towed to beaty Chevrolet (9615 parkside dr, knoxville, tn 37922) where he was informed that the voltage on the battery was low and needed to be replaced. The contact spoke to serra Chevrolet Cadillac Buick GMC Kia (189 stonebridge blvd, jackson, tn 38305) where the dealer discussed trading in the vehicle, but offered no assistance for the repair. The manufacturer was notified of the failure. The vehicle was not repaired. The failure mileage was 162,000.

- Knoxville, TN, USA

My 2012 Chevy Volt has completely shut off at freeway speeds, and surface streets on over 15 occasions. The power steering assist goes out, the brake assist goes out and it's very difficult to steer and break the car, I have nearly avoided several accidents, there is no warning that this will occur.the power steering assist goes out, the brake assist goes out and it's very difficult to steer and break the car, I have nearly avoided several accidents, there is no warning that this will occur once I have attempted to safely pull over the car says engine not available, propulsion power reduced, the car will not turn off and it says waiting to initialize on the screen. I have had it towed to my local Chevrolet dealership and paid a diagnostic, they have been unable to determine the cause of the problem and they just reset the car by unplugging the battery and tell me that they cannot replicate the issue.this does not happen while the car is driving on his hybrid battery, it only happens when driving in hybrid mode with the gas motor. In doing my own research, I found a recall campaign that describes the exact issue that has been occurring, it even states that the car may not be safe to drive if this occurs. Recall #18V397000. Each time I towed my Chevy Volt to the dealer it sat there for several weeks to a month, they returned it to me and the next day it died in the road. The car is not safe to drive, the dealer states that they can't diagnose the problem and I fear for my life every time I drive the car because it happens at random.

- Del Mar, CA, USA

Volt loses power when switching from electric to gas motor. Has no occurred two times, both resulting in a tow bill. Te Volt depletes the onboard battery charge and is then supposed to switch ove to the niternal combustion engine. Instead, at the time of transition the vehicle loses all propulsion power, power steering, etc. The car comes to a complete stop and will not move. This has happened on a multiple-lane freeway and is very dangerous trying to maneuver a vehicle that has no power to drivetrain or steering.

- Archbold, OH, USA

The car will shut itself off with very little time to get to the side of the road if that is even a possibility. When switching from battery power to the gas motor. Randomly. The car will die at any speed. First message is low propulsion power. Next message engine not available, service soon. Less than 4 minutes from 1st message to total shut down. Least amount of time between messages and shut down is 15 seconds. Car will decelerate (on highway where vehicles behind have no warning... no brake lights that car is rapidly losing speed). Never know when it will happen. Usually car will restart and run terrible.. after 20 minutes or so. After restart car runs bad low power. Check engine light is on. After 10 more minutes of driving. It straightens out. Usually. Dealership unable to find problem. Assorted codes in computer. Very dangerous when driving. Especially when it happens and it is 15 seconds to complete shut down. I have opened a case with Chevrolet. No response as of yet. They were supposed to call within 2 days. I will upload an attempt at restart as it is the only one I have where I was safely in a parking lot when it happened. Usually I am not. And many roads in my area do not have a shoulder.

- Rock Hill, SC, USA

Volt loses power when switching from battery to gas. Has now occurred four times. Each time Volt is traveling on highway 65+mph. Volt depletes battery charge and immediately upon transition to gas will lose all power. Cannot accelerate. Steering wheel loses power steering. Volt will decelerate until 0 mph. Very dangerous. In each instance driver is forced to get to shoulder or off freeway in Volt which is rapidly losing speed. Occurred on highway without shoulder last time. Almost caused a serious accident.

- Houston, TX, USA

Vehicle dies suddenly while moving, although under full electric charge. Could not restart. Chevy said was software problem and made fix Dec 2018. Just happened again yesterday 2/17. Others reported on Volt blog site. Said wait 5-10 minutes and then restart, which I did and that worked. Concern that loss of power is sudden and without warning. Died in middle of intersection this time but fortunately no cross traffic. This is serious problem -- apparently others have had same issue. Reporting to local Chevy dealer at this time.

- Honolulu, HI, USA

11/10/2018 while driving about 45mph heading school the car totally shut down for not reason, and would not restart. The ev mode shut down and the gas engine did not start. Police recommend to get it towed to safe location. Onstar records, multiple shut down of computer modules.

- Norfolk, VA, USA

The contact owns a 2012 Chevrolet Volt. While driving 70 mph, the vehicle stalled without warning and completely lost power. The vehicle was towed. In addition, the check engine indicator illuminated without warning. The vehicle was diagnosed, but the dealer could not duplicate the failure. The manufacturer was made aware of the failure. The failure mileage was 48,014.

- Saint Petersburg, FL, USA

I have owned the vehicle for 4.5 years. In the last two months the error message "propulsion power reduced" has happened and the vehicle has gone into lip mode. All three times the message occurred when the vehicle was started, battery depleted, and gas engine running. Drivabilty was an issue as the car was in limp mode and would not accelerate properly. My car was taken to the dealer, twice. I was told by jay townsend, district manager aftersales Chevrolet, that this is normal operation and he pointed to a bulletin. He said there is no fix, but that going into limp mode spontaneously was a " vehicle characteristic ". it is illogical that an error message popping up is normal "vehicle characteristics" and that going into limp mode is normal. This is a big problem that GM seems willing to accept. Obviously some parameters being broken is setting off the warning message, but GM doesn't want to address this. Instead they are stating it is normal operation. Someone is going to be hurt because of sudden reduction of power and GM's deliberate denial to fix the problem. I don't want this to be me or my family.

- Whitmore Lake, MI, USA

The car shut off completely while I was driving 65 mph on the freeway and had to be towed into the dealer for repair. It was determined by the dealer that an underhood fuse shorted out and burned into the vehicle battery charging system causing the car to shut down while driving. A major safety hazard as this could have caused an fire.

- Eastvale, CA, USA

The contact owns a 2012 Chevrolet Volt. While driving 60 mph, the vehicle stalled without warning. The vehicle was taken to the dealer for diagnostic testing. The technician diagnosed that there was a cylinder misfire. The vehicle was repaired. The manufacturer was not notified of the failure. The failure mileage was 42,000.

- Tacoma, WA, USA

Driving using cruise control during commute at 60mph. Simultaneously experienced drastic power loss and check engine light. Onstar diagnostics reported an electrical propulsion system malfunction. Attempted to navigate to a safe parking area but eventually lost all propulsion and ended up in a traffic lane. Significant impact to control especially in highway traffic that nearly resulted in a collision.

- San Marcos, TX, USA