This preliminary informational (PI) bulletin provides information to dealership personnel that may be helpful when addressing underbody component corrosion with customers.
full bulletin at NHTSA ↗2018 Chevrolet Volt powertrain problems
moderate Owners of the 2018 Chevrolet Volt have filed 82 NHTSA complaints about the powertrain, typically surfacing around 24,000 miles at roughly $2,500 to repair (U.S. federal records, as of July 2026). Source: NHTSA Office of Defects Investigation. See powertrain across all vehicles →
Failure mileage
Complaints
82
Recalls
0
Avg fix
$2,500
| Model year | powertrain complaints |
|---|---|
| 2014 Volt | 4 |
| 2015 Volt | 6 |
| 2016 Volt | 51 |
| 2017 Volt | 216 |
| 2018 Volt (this page) | 82 |
| 2019 Volt | 16 |
When does it fail?
Of the 82 powertrain complaints filed for the 2018 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
Powertrain accounts for 38% of every owner complaint on file for this vehicle — the dominant problem area across 7 categories tracked.
Owners have filed 82 powertrain complaints with NHTSA against this vehicle, but no formal recall covers the issue — the federal record reflects what manufacturers have admitted, not everything owners are reporting.
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.
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 ↗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 ↗Source: NHTSA manufacturer communications. Bring the bulletin number to your dealer or shop.
The failure pattern owners describe
Owners of 2018 Chevy Volts describe two categories of critical failures: propulsion loss and shutdown/park detection defects.
Propulsion and Power Loss: Drivers report sudden, unexpected loss of engine and/or electric motor power during highway driving at speeds ranging from 30 to 80 mph. The dashboard displays "Low Propulsion Power – Engine Not Available" or "Propulsion Power Reduced," check engine lights illuminate, and vehicles coast to stops in active traffic lanes or on freeway shoulders. Multiple diagnostic codes appear, pointing to BECM (Battery Energy Control Module), transmission, EGR valve, or high-voltage battery faults. In many cases, vehicles then refuse to restart or restart but will not shift into drive. Owners cite catalytic converter, EGR valve (on nationwide backorder), transmission assembly, and full high-voltage battery pack replacements as required repairs—some vehicles have sat at dealerships for over 5 months awaiting parts with no ETA.
Park-Shift Detection: A widespread, separate defect prevents the vehicle from recognizing it's in park when the shifter is in park. The dashboard displays "Shift to Park" or "Action Required: Shift to Park," the vehicle will not power off, and owners must jiggle the shifter or cycle through all gears (sometimes repeatedly over minutes) to shut down the car. One owner's vehicle moved backward while allegedly in park. This defect is intermittent initially but worsens over time, occurring with every parking cycle in some cases.
Safety Impact: Owners emphasize that propulsion loss occurs without warning on busy highways and in intersections, forcing coasting to stops surrounded by high-speed traffic. Inability to shut off the vehicle leaves it running unattended (draining battery, presenting theft risk, or filling a garage with exhaust). Both defects are well-documented in online forums and class action lawsuits, yet GM has issued only limited service bulletins and special coverage with inconsistent application.
Same Chevrolet Volt powertrain reports on nearby years: 2016 · 2017 · 2019
Failure modes owners describe
Shift to Park Detection Failure
Gear shifter position sensor or electrical circuit fails to recognize park position, leaving vehicle unable to power off despite shifter being in park. Often requires wiggling shifter or cycling through gears multiple times to register park. Electrical/mechanical defect in shifter assembly or position sensing.
When: Intermittent, during shutdown attempts; occurs across 11k–91k miles; worsens over time
Symptoms owners cite: Dashboard displays 'Shift to Park' or 'Action Required: Shift to Park' message when vehicle is already in park; Vehicle will not power off or shut down completely; Speedo display remains on; horn may sound inappropriately; Requires repeated manual shifter movements (cycling through RNDL) or jiggling to clear error; In rare cases, steering wheel freezes or vehicle loses drive function while message appears
Codes mentioned: N/A—position sensor or shifter circuit fault; not reported with DTCs
Repairs/costs cited: Dealership typically replaces shifter assembly or shifter in-line wire harness jumper; costs ~$500 for out-of-warranty repairs; parts readily available; repairs may recur after 2–3 days
Recalls/TSBs owners mention: Class action lawsuits filed against GM for widespread defect; some repairs covered under warranty initially; second/third replacements not covered; special bulletins issued but repairs often not performed proactively
Reduced Propulsion / Low Propulsion Power Warning
Vehicle loses significant driving power or all propulsion during operation, triggered by various electrical or engine management faults. Engine may shut down, refuse to start, or deliver severely reduced output. Warning message appears on dashboard; often accompanied by check engine light and multiple diagnostic trouble codes.
When: Typically within first 10–100 miles of driving; can occur after cold start, refueling, or spontaneously during highway driving; failure mileage ranges 5k–91k miles
Symptoms owners cite: Dashboard warning 'Low Propulsion Power - Engine Not Available' or 'Propulsion Power Reduced' message; Check engine light illuminates; Engine shuts down or refuses to start; vehicle coasts to stop; Severe power loss while accelerating or at highway speeds (e.g., unable to exceed 5–10 mph despite throttle input); In EV mode, loss of electric motor power despite adequate battery charge; Engine RPM fluctuates wildly; jerking or surging sensations; Secondary systems (heat, defrost, AC) become inoperative in reduced propulsion state
Codes mentioned: P0A46, P0AC4, P1E00, P1AF0, P1AF2, P1AEE, P1AEF, P1B0B, P1B43, P1E1E, P1E22, P1E5B
Repairs/costs cited: Root causes include faulty BECM (Battery Energy Control Module) replacement required; catalytic converter replacement; EGR valve replacement (nationwide backorder for months/years); transmission assembly replacement; battery module replacement; transmission fluid pump seal/filter/spacer plate replacement; O2 sensor replacement. Many parts on indefinite backorder with no ETA; repair costs range $1.6k–full battery pack replacement; vehicles stranded at dealerships for 3.5–5+ months awaiting parts
Recalls/TSBs owners mention: GM issued Service Bulletin (May 2021) for transmission/BCEM issues with no retroactive assistance; Special Coverage N232432680 applies to some vehicles for reduced propulsion but requires in-shop reproduction of fault to invoke; many repairs refused unless check engine light is actively illuminated at time of inspection; BECM failures covered under Voltec warranty but parts unavailable; repair demands on customers due to parts shortage
Engine Shutdown on Highway / Loss of Drive While in Motion
Vehicle loses all engine power and/or transmission function while driving at highway speeds, forcing coasting to shoulder. Often triggered by 'Shift to Park' or 'Propulsion Power Reduced' messages. Vehicle may refuse to restart or may restart but remain non-functional. Poses extreme safety hazard in high-speed traffic.
When: Unpredictable; occurs at 30–80 mph during normal highway operation or freeway exits; some instances occur immediately after repair of related fault
Symptoms owners cite: Sudden loss of engine and/or propulsion power while driving; 'Shift to Park' or 'Propulsion Power Reduced' message appears on dash; Check engine light illuminates; Vehicle will not restart or cycles through 'Initializing' repeatedly before rebooting without resolving issue; Transmission will not shift into drive or reverse; Vehicle coasts to complete stop in active traffic lanes; Multiple error codes retrieved post-incident relating to hybrid powertrain or transmission
Codes mentioned: P0A46, P0AC4, P1E00, P1AEE, P1AEF
Repairs/costs cited: Dealership diagnostics reveal transmission assembly fault, BECM failure, or hybrid powertrain electrical failure requiring full component replacement; parts unavailable; vehicles towed and stored at dealer for weeks to months; no interim loaner vehicles provided in some cases
Recalls/TSBs owners mention: No recall issued despite multiple incidents on same model year; some cases assigned GM case numbers for investigation but no proactive remedy; repair timelines unknown due to parts backorders
EGR Valve Failure
Exhaust Gas Recirculation valve fails, triggering reduced propulsion warnings and check engine light. Engine may shut down or refuse to restart. Part has been on nationwide backorder for extended periods (months to years), leaving vehicles immobilized.
When: Occurs during normal driving; failure mileage not consistently reported; backorder status ongoing as of complaint dates
Symptoms owners cite: Check engine light comes on; Reduced propulsion power warning displays; Engine shuts down or will not start; Vehicle loses all driving capability and must be towed
Codes mentioned: EGR valve diagnostic (specific codes not cited in narratives)
Repairs/costs cited: EGR valve replacement required; part is on nationwide backorder with no ETA; dealerships report waiting months to years for availability; in some cases valve was cleaned rather than replaced as interim measure but problem recurred; no substitute or upgrade part available
Recalls/TSBs owners mention: No service bulletin or special coverage cited for EGR failures; no interim support or loaner vehicles offered while waiting for backorder parts
Battery Energy Control Module (BECM) Failure
BECM electrical component fails, causing loss of propulsion power, inability to charge via PHEV port, and multiple diagnostic trouble codes. Failure renders vehicle inoperable and safety-critical. High-voltage battery pack may require full replacement. Part frequently on backorder.
When: Intermittent initially; becomes critical failure requiring tow; occurs at low mileage (11k) and higher (91k); sudden complete failure after warning phase
Symptoms owners cite: Check engine light and 'Propulsion Power Reduced' or 'Engine Not Available' warnings appear; Battery will not charge via PHEV charging port; Vehicle loses propulsion on one or both powertrains; Electric propulsion system performs unexpectedly (battery shows 100% when previously at 50%; battery shows full icon but 1 EV mile range); Lithium-ion battery not performing as expected (per OBD messages); Onboard charging system fault codes
Codes mentioned: P1E00, P1AEE, P1AEF, P0AC4, P1E5B, PIC6285B (troubleshooting aid)
Repairs/costs cited: Full BECM replacement or full high-voltage battery pack replacement (Part #24296900) required; parts on indefinite backorder with no ETA; repairs cost not specified but vehicles remain at dealerships 5+ months awaiting parts; some BECM failures covered under Voltec extended warranty if detected within coverage period; software reset of BECM/HPCM2 attempted but does not resolve underlying hardware defect
Recalls/TSBs owners mention: Special Coverage bulletins issued (e.g., N23243268, PIC6285B) for diagnosis but coverage application inconsistent—some claims refused if check engine light not actively illuminated at inspection or if customer does not qualify for extended warranty; manufacturer has confirmed failure but unable to provide parts within reasonable timeframe; no interim assistance or loaner vehicles offered
Fuse Blowout ('No Walk Home' Fuse)
Propulsion system fuse ('No Walk Home' fuse) blows during or immediately after refueling, causing sudden loss of engine power mid-drive. Blowing fuse triggers 'Low propulsion power' warnings and 'No fuel detected' message. Manual replacement resolves issue temporarily but recurs if engine shut off during refueling.
When: Occurs when vehicle is shut off while parked at fuel pump (gas mode); blows during subsequent drive after refueling; recurrence happens with repeated engine-off refueling cycles
Symptoms owners cite: Loss of drive power and engine shut down while accelerating after refueling; 'Low propulsion power - engine not available' and 'No fuel detected' warnings display; Engine starts, runs briefly, then dies repeatedly; Check engine light may illuminate
Codes mentioned: N/A—fuse fault; not reported with OBD codes
Repairs/costs cited: Replacement of 'No Walk Home' fuse resolves power loss temporarily; fuse can be sourced from aftermarket fuse sets; problem recurs if driver shuts off engine while parked at fuel pump; avoiding engine shutdown during refueling prevents recurrence
Recalls/TSBs owners mention: No service bulletin or recall issued; owner discovered fuse replacement solution via online forum; no manufacturer guidance provided
Catalytic Converter Failure
Catalytic converter fails, triggering 'Low propulsion power - engine not available' warning and forcing engine shutdown. Part requires replacement; out-of-stock status delays repair.
When: Occurs early in week of failure; can recur shortly after dealer repair if root cause not fully addressed
Symptoms owners cite: 'Low propulsion power - engine not available' dashboard warning; Engine shut down, vehicle becomes immobile
Codes mentioned: N/A—catalytic converter diagnostic (specific codes not provided)
Repairs/costs cited: Catalytic converter replacement required; part was out of stock at dealership with 3-week lead time; after initial repair, same fault recurred within days, suggesting underlying electrical issue may trigger repeated converter failures or fault codes; dealer then prescribed additional $1.6k in unrelated diagnostics (engine bay cleaning, brake system diagnostic)
Recalls/TSBs owners mention: No rental or loaner vehicle provided during 3+ week parts wait; no explanation for rapid recurrence after repair
Transmission Fault / Shift Failure
Transmission loses ability to shift gears or engage drive/reverse, leaving vehicle immobile despite engine starting. Often accompanied by high-pitched revving or transmission slipping. May be triggered by sensor faults (e.g., drive motor position sensor) or internal hydraulic/mechanical failure requiring full transmission assembly replacement.
When: Can occur after initial propulsion power loss events; occurs at 12k–32k miles; may follow brief normal operation after prior repair
Symptoms owners cite: Vehicle will not shift into drive or reverse despite shifter movement; Transmission revs high or jerks violently; Transmission does not engage proper gear ratio; Vehicle remains immobile after attempting multiple gear shifts
Codes mentioned: P0A46 (Drive Motor 2 Position Sensor Performance—primary code in multi-code event), P1B0B, P1B43, P1E1E
Repairs/costs cited: Full transmission assembly replacement required; replacement assembly is backordered with no ETA; vehicles remain immobilized at dealership for months; labor cost not specified; dealer recommends continued investigation while vehicle sits idle
Recalls/TSBs owners mention: Manufacturer assigned case numbers for investigation but no interim repair or loaner vehicle provided; no timeline for parts availability
Wheel Speed Sensor Damage / ABS System Fault
Driver-side wheel speed sensor becomes damaged during normal driving, causing sensor tip in hub to fail. Anti-click washer breaks and begins cutting sensor. Triggers abs, stabiltrack, and engine warning lights; vehicle enters limp mode with jerking and RPM surging.
When: Occurs during highway driving at 80 mph; single reported incident at unknown mileage
Symptoms owners cite: Vehicle jerks and RPM surges up and down; Adaptive cruise control disengages; Stabiltrack, ABS, and engine lights illuminate; Vehicle enters limp mode; Speedometer reading increases erratically (e.g., jumps to 90 mph while actual speed is lower); Check engine light activated
Codes mentioned: ABS/Stabiltrack/Engine codes (specific codes not provided)
Repairs/costs cited: Wheel speed sensor replacement required; anti-click washer failure noted as root cause of sensor damage; repair completed at dealership
Recalls/TSBs owners mention: No specific manufacturer response noted; repair handled via dealership warranty or out-of-pocket cost not specified
High-Voltage Battery System Fault / Lithium-Ion Battery Degradation
Lithium-ion high-voltage battery pack or onboard charging system fails, preventing vehicle from charging and rendering it inoperable. Multiple onboard diagnostic messages indicate battery and charging system faults. Battery module requires replacement but part is backordered.
When: Occurs after vehicle parked in garage all day; occurs without warning; sudden onset at unknown mileage
Symptoms owners cite: Vehicle fails to restart after parking; 'Lithium-Ion Battery is not performing as expected' message; 'Issue detected in Onboard Charging System' message; 'Vehicle network communication code' and network disruption messages; Multiple battery and integrated control module codes stored
Codes mentioned: Battery module fault codes (specific codes not provided in narrative; P1E00 likely involved)
Repairs/costs cited: Full battery module or high-voltage battery pack replacement required; part is backordered with unknown delivery date; vehicle immobilized at dealership pending parts availability
Recalls/TSBs owners mention: No warranty or special coverage noted; customer responsible for full replacement cost; no interim support or loaner vehicle offered
Synthesized from 82 NHTSA owner complaints — unverified consumer allegations, summarized for patterns. The verbatim filings appear below.
What owners are reporting 8 most recent
Initially was receiving intermittent “Recieved Propulsion Power” warning and no check engine light. Did it about every 2 weeks but became worse. Received Reduced Propulsion power warning on a road trip from East TN to Charlotte then showed a check engine light. I continued to Charlotte I had 4 miles left on battery and was running on gas engine when “Engine Not Available” warning came on…
My 2018 Chevrolet Volt frequently fails to recognize when the vehicle is shifted into Park. The dashboard displays “Shift to Park” even though the gear selector is already in Park. When this occurs, the vehicle will not power off, requiring multiple attempts to move the shifter before shutdown is possible. This creates a safety risk because the vehicle may be left powered on unintentionally and…
On Dec 3, 2023 I got the message "Propulsion Power is Reduced" and the gas engine started even though there was about 53 miles left in the battery. I was able to continue on to my destination use the gas engine. On Dec 8, 2023 I drove the car to La Quinta Chevrolet and they diagnosed the problem as a failed BECM (Battery Energy Control Module). On Dec 11 I got the car back and was told the BECM…
Vehicle is 2018 Chevrolet volt with approx 91000 miles, purchased new in California with both PZEV and Voltec warranties in place. Vehicle produced MIL in December, in Colorado, with exterior temperatures ~30 degrees, after attempting to remote start. The resulting OnStar Codes P1AEE, P1AEF, and P0AC4 indicating "the electric propulsion system is not performing as expected. Please service…
Shift to park issue. When the car is in park the car still reports shift to park when you try to turn it off.
On June 27, 2025, while driving, the vehicle displayed a "Propulsion Power Reduced" warning message and a Check Engine Light illuminated. I immediately experienced a loss of power. I brought the vehicle to an authorized Chevrolet dealer the same day. On July 1, 2025, the dealer diagnosed the failure as a faulty Battery Energy Control Module (BECM) and high-voltage system fault (Code P1E00),…
In August 2023, while driving on I-93 in Boston, car switched from Battery Mode to Engine Mode, and Driver Information Screen reported "Reduced Propulsion". Propulsion Battery charge and gasoline fuel levels were adequate such that this should not have happened. In this Reduced Propulsion state the environmental systems, i.e. Heat/Defrost/AC, become inoperative. A thunder storm overhead was…
My 2018 Cheverolet Volt stopped charging via the PHEV port, the check engine light came on, and "Propulsion Power Is Reduced" read on the driver display. Car acceleration began to lag and I called the dealership service department immediately. I took it to the service dept and they said the repair is under warranty but the part is back-ordered with no ETA on when I will get my car back, but I…
Had powertrain trouble with your 2018 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 2018 Chevrolet Volt?
It's a documented issue but not catastrophic. 82 complaints have been filed. Repairs average $2,500 and most owners catch it before it causes a breakdown.
At what mileage does the powertrain typically fail?
Across the 20 complaints that reported odometer mileage, most powertrain failures cluster between 15,300 and 33,300 miles, with the median around 24,000. A quarter of owners report trouble before 15,300; a quarter make it past 33,300. 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/2018/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.