This service bulletin provides information on some vehicles that may rock or move slightly forward or rearward while in Park at start up after cold soak. This condition may be accompanied by a clunk noise. This is a slight movement that is more often seen visually, rather than felt, when viewed from the outside and using the auto-start feature, if equipped.
full bulletin at NHTSA ↗2012 Chevrolet Volt powertrain problems
severe 20 complaints filed with NHTSA · avg repair $2,500 · see powertrain across all vehicles →
Failure mileage
Complaints
20
Recalls
0
Avg fix
$2,500
2injuries
When does it fail?
Of the 20 powertrain complaints filed for the 2012 Chevrolet Volt, here's the actual mileage breakdown — failures cluster heaviest at 0-25,000 mi.
0-25k
25-50k
50-75k
75-100k
100-125k
125-150k
150k+
Each bar shows the share of total complaints filed at that mileage range. Peak failure window highlighted. Some owners report problems earlier; some make it well past 150,000 miles symptom-free. Maintenance habits and driving conditions shift the curve as much as mileage alone.
What stands out
No new NHTSA powertrain complaint has been filed on this vehicle in over 6 years — the issue may be aging out of the active population.
Is there a fix? Manufacturer service bulletins
The manufacturer has issued service bulletins covering powertrain on this vehicle — documented repair instructions, service campaigns, or warranty extensions sent to dealers. A TSB isn't a recall (it's not a free safety remedy), but it's the manufacturer acknowledging the issue and how to fix it.
GM is receiving damaged (cracked or broken) transmission cores returned to the reman facilities. The damage is being caused either in the removal process by the technician, or inadequate packaging or shipping. This bulletin advises the dealers to be more careful not to damage the transmissions during removal and to package the core properly for return.
full bulletin at NHTSA ↗This service bulletin provides information on Driveline Clunk Noise and what is acceptable and what is considered normal operation.
full bulletin at NHTSA ↗This bulletin provides information on the harmful effects of water or ethylene glycol in transmission fluid.
full bulletin at NHTSA ↗This service bulletin provides technicians with information to help identify the differences between what is considered a fluid leak, and what is considered fluid seepage.
full bulletin at NHTSA ↗Source: NHTSA manufacturer communications. Bring the bulletin number to your dealer or shop.
The failure pattern owners describe
The 2012 Volt's powertrain exhibits multiple failure patterns that create real safety risk. Most serious is sudden complete power loss at any speed with no warning—power steering and brake assist both fail, forcing drivers to pull off dangerous roads. This happens in hybrid mode (gas engine running) and occurs at random intervals; one owner reported 15+ incidents. GM's recall 18V397000 addressed this exact problem, yet owners report the issue recurring months after the repair was performed, with dealers and even GM field engineers unable to find or fix the root cause.
Shifter problems run deep. The gear selector fails to fully engage the mechanical Park lock despite showing Park on the display, letting vehicles roll or shift into Reverse unintended. Storage items in the console physically block the shifter from traveling the full 2 inches needed for mechanical engagement. One owner received a serious electrical shock from the shifter after a dealer repair; GM rerouted him to a legal/claims department instead of investigating.
Battery thermal management is chronically broken. Owners report the coolant system leaking on a predictable 12-month cycle, with dealerships unable to permanently repair it despite replacing components and connections. The drive motor rotor bearing fails routinely, especially in Gen1 models; it's common enough GM issued a service bulletin for it. Unintended acceleration after battery service, stalling at any speed, and transmission bracket fracture at low mileage round out a powertrain that requires vigilance and deep pockets.
Same Chevrolet Volt powertrain reports on nearby years: 2013
Failure modes owners describe
Sudden Loss of Propulsion/Power Shutdown
Vehicle loses all propulsion power while driving at highway or surface speeds, with power steering and brake assist going out. Engine displays 'Propulsion Power Reduced' or 'Engine Not Available' messages. Switching between electric and gas motor does not occur properly. Vehicle will not turn off and displays 'Waiting to Initialize' on screen.
When: Multiple occurrences over vehicle lifetime; reported at 91,064 miles on one recalled vehicle; one complaint at 45 mph on busy road
Symptoms owners cite: Complete power loss while driving; Power steering assistance lost; Brake assist lost; Propulsion Power Reduced warning message; Engine Not Available message; Vehicle difficult to steer and brake; No warning before occurrence; Occurs randomly in hybrid mode with gas motor; Does not occur on electric battery alone
Codes mentioned: Recall #18V397000, GM Program # N172130462
Repairs/costs cited: Dealership unable to diagnose or replicate issue; reset by unplugging battery; one dealer kept vehicle 5.5 months without resolution; one complaint resolved by transmission attention but dealer unable to pinpoint exact cause
Recalls/TSBs owners mention: Recall #18V397000 issued for exact condition; Recall GM Program # N172130462 performed but problem recurred; GM field engineer unable to resolve despite involvement
Shifter/Transmission Mechanical Failure
Gear shifter malfunctions including stiffness and failure to fully engage Park detent. Electronic controls activate transmission to Park and unlock doors/light indicator, but mechanical locking pin does not engage fully. Shifter can be pulled back into Reverse without driver present. Storage items in console can physically block shifter from reaching mechanical Park detent.
When: One electrocution incident occurred about three weeks after shifter repair; another incident with unintended vehicle movement at parking lot
Symptoms owners cite: Stiff or difficult shifter operation; Shifter does not reach full mechanical Park engagement despite electronic signals showing Park; Vehicle can roll from Park or shift into Reverse unintended; Vehicle lunges forward unintentionally after battery service
Repairs/costs cited: Dealer mechanic replaced shifter part; one dealer duplicated problem but refused to document after management discussion; another dealership (Kelsey Chev, Lawrenceburg, IN) unable to fix; shifter needs approximately 2 additional inches travel to reach mechanical lock-in detent
Electrical Shock Hazard at Shifter
Driver received significant electrical shock when depressing gear shifter button to place car in Park after returning home. Shock caused involuntary muscle reaction, pain, numbness, and tingling in hand and arm. Vehicle had previous battery component malfunction that was being serviced.
When: Three weeks after dealership shifter repair
Symptoms owners cite: Electrical shock to hand/arm at shifter contact point; Pain and shock sensation; Soreness; Numbness; Tingling sensation in hand and arm
Repairs/costs cited: GM instructed driver to call 911; Fire Department refused to cut power cables citing lack of knowledge and safety concerns; driver able to remove hand contact before involuntary muscle contraction could occur
Recalls/TSBs owners mention: GM transferred driver to product allocation/legal department for claim investigation after incident reported to GM
Hybrid Battery Coolant Leak - Recurring
Primary electric (lithium-ion) battery coolant system develops repeated leaks at approximately 12-month intervals. Dealership unable to locate and permanently fix leak; temporary refilling with fluorescent dye added in 2013, repairs attempted in 2014, connections replaced in 2015, yet problem recurs annually. Before warning light, cooling fan runs longer during charging and A/C stops blowing cold.
When: First detected June 2013 (approximately 7 months after November 2012 purchase); recurred 2014, 2015, 2016 on annual cycle
Symptoms owners cite: Warning light comes on; Cooling fan runs longer while charging; A/C stops blowing cold; Coolant loss requiring ~7 liters replacement each time
Repairs/costs cited: 2013: Coolant refilled (~7 liters); 2014: Coolant refilled (~7 liters); 2015: Substantial coolant system components around battery replaced, claimed to find leaky connections; 2016: All new coolant replaced
Drive Motor Rotor Bearing Failure
Bearing cage in electric drive motor (Motor B) rotor bearing separates or fails, causing loud whining noise during highway driving or regenerative braking. Technicians describe it as 'common' issue in Gen1 Volts. GM issued service bulletin requiring revised bearing installation. Bearing failure is likely stress-related to regenerative braking; Gen1 models lack customizable regenerative braking option to reduce rotor bearing stress.
When: One complaint at approximately 71,000 miles; another with warranty expired by less than one year and 11,000 miles (total mileage unknown); one more complaint with no specific mileage
Symptoms owners cite: Extremely loud whining-like sound from driver's side front wheel during highway driving; Loud audible whining noise from engine compartment during braking and passive deceleration; Bearing cage separation
Repairs/costs cited: Revised bearing installation required; GM Service Bulletin No. PIP5081L (evolved to Letter L revision); dealer describes as requiring 'new/revised bearing installation'; one owner's warranty expired before repair could be performed
Recalls/TSBs owners mention: GM Service Bulletin PIP5081L (latest revision Letter L) issued; large number of owners qualify for warranty repair if within coverage period
Transmission Bracket Fracture/Detachment
Transmission mounting brackets fractured at approximately 20,000 miles, causing transmission to become detached from engine. This caused brake pedal to become unresponsive intermittently. Vehicle was not included in related NHTSA recall campaign.
When: Approximately 20,000 miles
Symptoms owners cite: Brake pedal did not respond (intermittent); Transmission brackets fractured
Codes mentioned: Not included in NHTSA Campaign #13V271000 (Electronic Stability Control, Service Brakes)
Repairs/costs cited: Vehicle towed to dealer for inspection and repair
Recalls/TSBs owners mention: Manufacturer notified of failure
Battery Thermal Management/Charging System
Battery refuses to charge after warning for 'Service High Power Charging System.' Coolant levels low despite owner adding coolant to reservoir. Related to high-power charging system malfunction.
When: Timing not specified
Symptoms owners cite: Service High Power Charging System warning message; Low coolant levels; Vehicle refuses to charge even after coolant added
Repairs/costs cited: Owner added coolant to reservoir without resolution
Continuous Stalling at Any Speed
Vehicle continuously stalls out regardless of driving speed. Power can only be restored by shifting to low gear then back to drive.
When: Timing not specified
Symptoms owners cite: Continuous stalling at any speed; Loss of power
Repairs/costs cited: Workaround: shift to low gear then back to drive to restore power
Unintended Acceleration After Battery Service
Vehicle lunges forward unintentionally at traffic stop, occurring multiple times. Problem began after battery service was performed. Vehicle also fails to enter regeneration mode properly during deceleration, a new symptom appearing after battery service.
When: Began within one month after battery service
Symptoms owners cite: Unintended forward acceleration at stop; Vehicle lunges forward multiple times at intersection; Failure to enter regeneration mode during deceleration
Repairs/costs cited: Owner threw vehicle into Neutral to stop lunging; problem occurred three times since battery service
Reverse Engagement Malfunction
After shifting into Drive on flat surface and pressing accelerator, vehicle moves backward as if in Reverse. Repeated shifting between P, R, and D does not correct behavior until vehicle is turned off and back on multiple times.
When: Timing not specified
Symptoms owners cite: Vehicle goes backward when Drive is selected; Transmission does not respond to gear changes
Repairs/costs cited: Only turning vehicle on and off multiple times brought it back to normal
Chronic Software/Electrical Issues Requiring Repeated Updates
Vehicle has ongoing problems with power propulsion and electrical system since new. Multiple components replaced in 2017; extended warranty covered repairs. However, vehicle continues to require software updates to operate properly. Once warranty expires, dealer charges for update installations. In 2017, vehicle sounded like it would blow up on startup, would not shut off, and required OnStar remote shutdown to stop.
When: Since new; updates performed 10/10/2018, 11/11/2019, and 8/28/2020
Symptoms owners cite: Power propulsion problems; Electrical system issues; Start-up issues; Rough/abnormal engine sound at startup; Unable to shut off engine without OnStar assistance; Requires yearly software updates to operate
Repairs/costs cited: Multiple items replaced; extended 6-year/100,000-mile warranty purchased; dealer performs updates; several items replaced in 2017 after OnStar emergency shutdown; dealer now charges for update installations after warranty expiration
Synthesized from 20 NHTSA owner complaints — unverified consumer allegations, summarized for patterns. The verbatim filings appear below.
What owners are reporting 4 most recent
Radiator leak
2012 Chevrolet volt, the vehicle has been losing power for propulsion on the highway/roads at all speeds. Shutting off. Electric charge is supposed to switch to the gasoline motor when it is low, but it does not, and vice versa. It shows hybrid battery management has a loss of propulsion with a message of low propulsion power. The original problem was not fixed with a recall a few years back…
The vehicle continuously stalls out at any speed the only way to get power back is by putting the car in low gear and then back into drive.
Driver had returned home, stopped car, depressed gear shifter button to put gear in park, and was electrocuted from the point of gear shifter. The vehicle was already slated to be "repurchased" by gm due to other ongoing mechanical malfunction issues. The vehicle was returned to the driver for use while the new vehicle was being built by gm for delivery to the driver. When the vehicle was at…
Had powertrain trouble with your 2012 Chevrolet Volt?
File a complaint with NHTSA → It's free, official, and how every report above got here — owner filings are the federal safety record this page is built on.
Common questions
How serious is the powertrain problem on the 2012 Chevrolet Volt?
It's a meaningful issue. 20 complaints have been filed and the failure mode causes operational problems for owners. Repairs average $2,500.
At what mileage does the powertrain typically fail?
Across the 16 complaints that reported odometer mileage, most powertrain failures cluster between 35,000 and 100,000 miles, with the median around 67,000. A quarter of owners report trouble before 35,000; a quarter make it past 100,000. Maintenance history matters more than the odometer alone — this is the reported failure window, not a guarantee.
What does it cost to fix?
Independent shops typically charge around $2,500 for powertrain repairs on this vehicle. Dealer pricing tends to run 20-40% higher. The exact figure depends on the specific failure mode, parts availability, and your local labor rates. If you're outside factory warranty, an extended service contract often covers this category.
Are there any recalls related to powertrain?
No active recalls currently cover powertrain issues on this vehicle. The complaints filed represent owner-reported failures that haven't risen to the level of a manufacturer-issued recall — but they're still worth knowing about before you buy or budget for repairs.
Related
Complaint and recall data sourced from the National Highway Traffic Safety Administration (NHTSA)
public records database. Verify the raw federal record at
nhtsa.gov/vehicle/2012/Chevrolet/Volt.
Severity ratings are derived from reported crashes, fires, injuries, and fatalities. Repair cost estimates are
independent-shop national averages and may differ in your area. Some links on this page are affiliate links.