On certain Model 3 vehicles, the positive busbar nut under the power conversion system and additional bolts within the High Voltage (HV) battery ancillary bay were insufficiently torqued during manufacturing.
full bulletin at NHTSA ↗2018 Tesla Model 3 powertrain problems
severe 24 complaints filed with NHTSA · avg repair $2,500 · see powertrain across all vehicles →
Failure mileage
Complaints
24
Recalls
0
Avg fix
$2,500
5crashes
1fire
What stands out
Of the 7 model years of Tesla Model 3 we track for powertrain problems, this one carries the most owner complaints on file — 24.
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.
Some Model 3 vehicles were built without a hydraulic control unit (HCU) wake-up wire, and in rare circumstances, braking and stability control related alerts may appear on the instrument cluster and touchscreen during the vehicle power-on process. Such faults can typically be corrected and the affected functionality restored with a vehicle power cycle.
full bulletin at NHTSA ↗Source: NHTSA manufacturer communications. Bring the bulletin number to your dealer or shop.
The failure pattern owners describe
Owners of the 2018 Model 3 describe powertrain failures that go beyond typical component wear. The most dangerous involve complete propulsion loss while driving—vehicles losing all power mid-highway, displaying "Unable to Drive" warnings, and becoming immobilized for 10–20 minutes before mysteriously resuming operation with no repair applied. Tesla has internally documented this as a "known characteristic related to cruise control use," yet the interim solution (exit the car and re-enter to resume) is neither safe nor practical on busy roads.
Unintended acceleration incidents cluster heavily: vehicles lurching forward suddenly with no pedal input, in parking lots, at traffic lights, and during slow-speed maneuvers. Owners report collisions with other vehicles, concrete structures, and buildings, with some incidents involving airbag deployment. No owner describes successful diagnosis or correction of the underlying cause.
Battery thermal management components fail prematurely. PTC heaters shut down vehicles after 6 years; high-voltage service panels and power conversion systems reduce charging capacity or fail entirely after 3–4 years. Owners note Tesla initially denied warranty coverage on thermal components despite their placement within the battery assembly and role in protecting the high-voltage system. Repair costs run $1,100–$2,000 per component when paid out-of-pocket.
Several owners report Tesla's delayed or non-responsive communication after reporting these safety issues, particularly when attorneys were involved. Firmware updates were applied post-collision without full transparency on what was actually changed.
Same Tesla Model 3 powertrain reports on nearby years: 2021
Failure modes owners describe
Complete Powertrain Loss / Drive Shutdown
Vehicle loses all propulsion and goes unresponsive while in motion, displaying warnings like 'Unable to Drive' and 'Vehicle Shutting Down' before stopping abruptly on the road. Owners report the car becomes immobilized for minutes with no ability to shift to neutral or restart immediately. Tesla's documented 'known characteristic' allegedly tied to cruise control use.
When: While driving at highway and local road speeds; also after cold overnight software update; one instance after 6 years/63,617 miles
Symptoms owners cite: Complete loss of propulsion while in motion; Display messages 'Unable to Drive, Pull Over to Safety' and 'Vehicle Shutting Down'; Vehicle unresponsive for 10-20 minutes before resuming operation without repair; Inability to shift to neutral when powered down; No ability to disengage or restart vehicle immediately
Codes mentioned: BMS_a035: Vehicle may not restart
Repairs/costs cited: Tesla service invoices acknowledge issue as 'scheduled to be fixed in 2019.20' but advised owners to 'exit vehicle and re-enter to resume operation' — advice owners called illegal and unsafe. No actual repairs completed in some cases.
Recalls/TSBs owners mention: Tesla acknowledged this as a 'known characteristic related to use of cruise control' per engineer statement. Scheduled fix deferred; interim solution deemed unsafe by owners.
Unintended Acceleration
Vehicle accelerates suddenly and uncontrollably without driver input on the accelerator pedal, occurring during parking maneuvers, slow-speed driving in parking lots, and after coming to a complete stop in traffic. Multiple incidents reported including one with collision.
When: At ~17,000 miles; during parking and low-speed driving; while stopped at traffic light; in underground garage at ~5-10 mph; multiple repeat incidents for same owner over months/years
Symptoms owners cite: Sudden acceleration without accelerator pedal being pressed; Wide-open throttle type acceleration described; Occurs during parking maneuvers and low-speed traffic situations; No warning lights illuminated prior to event; Vehicle lurches forward with sudden jerking motion
Repairs/costs cited: Vehicle involved in collisions with other cars and concrete structures. Owner reported hitting bushes, bumpers, headlights, and benders required repair. Body shop repairs completed but underlying cause not diagnosed or addressed.
Recalls/TSBs owners mention: Manufacturer informed of failures; referred owner to body shop for collision repair. No technical investigation or powertrain correction documented.
PTC Heater Failure
Positive Temperature Coefficient heater fails, cutting power supply to the 12V battery charging system (PCS), causing complete vehicle shutdown and inability to respond to commands or charging. This is the thermal management component protecting the high-voltage battery. Owner notes this failure was treated as a design flaw in Canadian small claims cases.
When: After 6 years/63,617 miles; overnight following software update; also reported as ongoing problem in 3-4 year old vehicles as of 2024
Symptoms owners cite: Vehicle enters 'Asleep mode' and will not turn back on; Display message 'Vehicle may not restart'; All systems shut down; locked out; Will not respond to key fob or software commands; Will not charge; charger cannot be released from charge port; 12V battery drains due to PCS disconnection
Codes mentioned: BMS_a035: Vehicle may not restart
Repairs/costs cited: Repair quoted at $1,104.18 including PTC Heater Dualzone and HVAC PTC service assembly replacement plus labor. Online diagnostics point to resistance issue in one of five heating elements within the PTC heater unit.
Recalls/TSBs owners mention: Canadian small claims filings deemed the PTC heater failure a design flaw and safety issue. Owner indicates Tesla does not cover this under battery warranty despite it being part of the thermal management system.
High Voltage Service Panel Failure
High-voltage service panel (part of the battery and drivetrain warranty) fails to allow full-amperage charging. Battery receives insufficient current during charging. Owner reports repair costs of $1,800–$2,000 and notes this has become a widespread issue across Model 3s after 3–4 years of ownership, particularly affecting those using frequent Supercharger sessions.
When: After 2+ years of ownership; particularly following heavy Supercharger use during long road trips; widespread in vehicles 3-4 years old as of 2024
Symptoms owners cite: Battery stops receiving full amperage during charging; Charging capacity diminished; Issue has persisted for 2+ years without resolution; Potential safety concern regarding fire risk during Supercharger or Level 2 home charging sessions
Repairs/costs cited: Repair cost estimated at $1,800–$2,000. Owner unsure if repair entails full battery replacement or opening the battery unit. Tesla initially refused to cover under battery system warranty despite panel location on the battery.
Recalls/TSBs owners mention: Tesla refused warranty coverage, claiming the panel is separate from the battery system despite its location atop the battery unit. No TSB or safety recall identified by owner.
Power Conversion System (PCS) Charging Failure
Power Conversion System fails to charge the vehicle at rated amperage. Vehicle defaults to lower charging rates and falsely reports grid or EVSE issues rather than identifying the internal component failure. Charging may fail without warning. One owner notes a service bulletin (MC-10148850-9999) exists but applies only to a limited production date range, leaving vehicles outside that window without remedy.
When: Issue started while vehicle was still under warranty; widespread issue; some vehicles manufactured outside the date range covered by service bulletin
Symptoms owners cite: Charging limited to lower amp rating (e.g., 32 amps instead of 48 amps); Display message 'Power Grid or Vehicle issue limiting the AC charging'; Charging fails without warning; Vehicle incorrectly reports external power issue rather than internal PCS fault
Repairs/costs cited: Service bulletin MC-10148850-9999 specifies Power Conversion System replacement. Repair costs not explicitly stated in narratives, but owner notes bulletin limited to certain production dates, leaving affected owners without coverage.
Recalls/TSBs owners mention: Service bulletin exists but only for vehicles within a specific production date range. Vehicles manufactured outside those dates experiencing the same failure lack warranty or recall coverage.
Brake/Throttle Dual-Pedal Power Restriction with Delayed Release
When brake and throttle pedals are depressed simultaneously, the vehicle reduces motor output as a safety measure but does not immediately restore power when the brake is released. A delay of several seconds persists during which the driver expects full acceleration but cannot achieve it, creating a dangerous traffic situation. Vehicle may also roll backward on steep inclines during this restriction window.
When: During normal driving and merging maneuvers; ongoing issue not tied to specific mileage
Symptoms owners cite: Motor output greatly reduced when both pedals pressed; Warning raised on display when both pedals activated; Power restriction persists several seconds after releasing brake pedal; Driver left in precarious position in traffic unable to accelerate as expected; Vehicle rolls backward downhill on steep inclines during restriction period
Repairs/costs cited: Owner reports the only workaround is pressing the park button on the right control stalk to stop rolling during restriction.
Rear Motor Drive Unit Failure with Cascading Faults
Rear motor drive unit fails, triggering replacement. Shortly after service completion, multiple cascading fault codes emerge including power limitation and acceleration/deceleration warnings. Owner expresses concern that underlying electrical or thermal issues cannot be properly diagnosed and may lead to propulsion system failure or unexpected thermal event while vehicle is in use or parked.
When: First failure code BMS_a035 triggered replacement; cascading codes appeared within 48 hours of service completion
Symptoms owners cite: Motor drive unit failure requiring replacement; Cascading fault codes after service: BMS_a027 (Power limited), BMS_a170 (de)acceleration and top speed warnings
Codes mentioned: BMS_a035: Vehicle may not restart, BMS_a027: Power limited, OK to drive, BMS_a170: Deceleration warning & top speed warning
Repairs/costs cited: Rear motor drive unit replaced. Owner was not given opportunity to inspect serviced components upon request. Multiple fault codes appeared within 48 hours suggesting incomplete diagnosis or recurring systemic issue.
Uncontrolled Acceleration While Parking
Vehicle accelerates uncontrollably during parking maneuvers when driver applies only slight accelerator input. One incident involved vehicle jumping over sidewalk and crashing into a building with airbag deployment.
When: During parking maneuvers; one instance noted as single incident in complaint
Symptoms owners cite: Sudden uncontrolled acceleration while parking; Vehicle jumps over sidewalk; Airbags deployed upon impact with building
Repairs/costs cited: Vehicle and building severely damaged. Airbag deployment occurred.
Shift to Gear Failure / Cannot Maintain Vehicle Power
Vehicle parked but unable to shift into Drive or Reverse, displaying message 'Cannot Maintain Vehicle Power.' Vehicle completely immobilized while parked, preventing normal operation.
When: While vehicle was parked
Symptoms owners cite: Vehicle will not move to gear (Drive or Reverse); Display message 'Cannot Maintain Vehicle Power'; Complete immobilization in parked state
Power Reduction Mode Activation / Coolant Leak Near Battery
Vehicle enters 'Power Reduction Mode' — a safety limiter — following coolant leak detection near the high-voltage battery. Tesla service advisor confirmed failure 'most likely related' to the battery thermal management system. Vehicle remains in reduced-power state; Tesla refused warranty coverage despite the thermal management system being integral to battery protection and falling under the 8-year/120,000-mile battery warranty.
When: March 21, 2025; vehicle still in service center unrepaired
Symptoms owners cite: Vehicle enters Power Reduction Mode; Coolant leak near battery area detected; Thermal management system failure suspected
Repairs/costs cited: Repair remains unapproved and unperformed; issue unresolved as of complaint filing.
Recalls/TSBs owners mention: Tesla refused to cover repair under battery warranty despite service advisor's written confirmation that failure was 'most likely related' to the battery thermal management system.
Vehicle Fire in Driveway
Vehicle caught fire while parked in the driveway approximately 4 hours after the last trip, resulting in significant damage and window breakage. Fire department extinguished the fire within 15 minutes. Security footage provided to fire department and Tesla engineering team.
When: January 9, approximately 4 AM; last trip was 10 hours prior to parking
Symptoms owners cite: Vehicle fire while parked; Fire broke out spontaneously in driveway
Repairs/costs cited: Fire department response required; vehicle sustained fire damage including broken windows.
Recalls/TSBs owners mention: Tesla engineering team received security footage for investigation; no resolution or findings documented in complaint.
Random Braking on Autopilot
Vehicle randomly applies hard braking while on Autopilot on the highway without any obstruction or forward vehicle present, creating sudden deceleration hazard.
When: During highway Autopilot operation; ongoing issue
Symptoms owners cite: Vehicle brakes instantly on Autopilot without warning; Occurs when no vehicle in front; Random sudden deceleration while on highway
Rear Camera Feed Delay Causing Collision
Rear-view camera feed freezes or delays by approximately one second while backing vehicle, resulting in crash into fixed object (shelf/structure). Owner attributes issue to software version 2023.12 and notes vehicle increasingly relies on cameras for ADAS functions.
When: After software version 2023.12 installation
Symptoms owners cite: Rear camera feed delayed by ~1 second; Camera feed froze while backing; Loss of real-time visibility for reversing
Repairs/costs cited: Vehicle collision damage sustained while backing.
Unexpected Forward Movement at Traffic Light on Downgrade
Vehicle with foot firmly on brake at a traffic light on a downgrade suddenly began moving forward into cars stopped ahead, despite driver attempting emergency braking and emergency brake application. Collision occurred; forward vehicle ultimately stopped the Tesla.
When: February 2019; purchased December 2018
Symptoms owners cite: Vehicle moves forward while driver has foot on brake; Vehicle unresponsive to brake and emergency brake pedal; Vehicle continues forward into stopped traffic; Collision with vehicle in front
Repairs/costs cited: Vehicle collision repairs performed at body shop. After repairs, sent to Tesla service center. Firmware update subsequently applied with statement 'Vehicle now safe to drive.'
Recalls/TSBs owners mention: Tesla sent firmware update after collision and advised vehicle was 'safe to drive at this time.' Attorney requested preservation of electronic driving records; request was not answered by Tesla service. Multiple contact attempts by attorney to Tesla service, customer service, legal, and headquarters went unanswered for months.
Unintended Acceleration While Merging from Parallel Parking
While attempting to merge into traffic after exiting a parallel parking space, vehicle suddenly accelerates uncontrollably when driver applies slight accelerator input. Owner reports this is not the first occurrence of this type of unintended acceleration in the vehicle.
When: While merging from parallel parking; recurring issue
Symptoms owners cite: Sudden uncontrolled acceleration when accelerator slightly depressed; Vehicle accelerates far more than driver input warrants; Recurring issue, not isolated incident
Brake Hold Feature Allows Unintended Gear Shift
Brake Hold feature (which keeps vehicle at standstill without holding brake pedal) can be overridden by moving the right steering column stalk to shift from Drive to Reverse (or vice versa) without requiring the vehicle to be placed in Neutral or Park first. This design allows unintended gear changes that could cause unexpected vehicle motion.
When: Ongoing design issue in vehicle
Symptoms owners cite: Right steering column stalk can shift from D to R without engaging P or N; Brake Hold does not prevent this unintended gear shift behavior
Severe Structural and Battery Damage from Prior Accident Not Disclosed at Sale
Vehicle purchased from third-party dealership (Choice Automotive LLC, Honolulu) with extensive hidden damage from prior accident: severe punctures to battery pack, damage to drive unit and subframe. Damage discovered immediately after purchase when warning light activated. Dealership failed to disclose accident history or damage. Tesla repair estimate: $20,000.
When: Discovered immediately after purchase from third-party dealership
Symptoms owners cite: Warning light illuminated upon reaching home; Extensive damage to drive unit, subframe, and battery pack with severe punctures
Repairs/costs cited: Tesla repair estimate $20,000 for drive unit, subframe, and battery pack replacement. Owner seeking legal action against dealership for sale of undisclosed accident vehicle.
Synthesized from 24 NHTSA owner complaints — unverified consumer allegations, summarized for patterns. The verbatim filings appear below.
What owners are reporting 0 most recent
Had powertrain trouble with your 2018 Tesla Model 3?
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 Tesla Model 3?
It's a meaningful issue. 24 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 8 complaints that reported odometer mileage, most powertrain failures cluster between 13,350 and 17,000 miles, with the median around 15,000. A quarter of owners report trouble before 13,350; a quarter make it past 17,000. 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/2018/Tesla/Model 3.
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.