DTC P18B1 STORED IN THE SHIFT CONTROL UNIT IF YOU CONFIRM DTC P18B1 for âCONTROL MODULEâ is stored in the Shift Control Unit. ACTION Follow the SERVICE PROCEDURE in this bulletin to: 1. Confirm the current Shift Control Unit part number. 2. Reprogram the Shift Control Unit, if applicable.
full bulletin at NHTSA ↗2020 Nissan Leaf powertrain problems
moderate Owners of the 2020 Nissan Leaf have filed 12 NHTSA complaints about the powertrain 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 →
Complaints
12
Recalls
0
Avg fix
$2,500
| Model year | powertrain complaints |
|---|---|
| 2018 Leaf | 3 |
| 2019 Leaf | 12 |
| 2020 Leaf (this page) | 12 |
| 2021 Leaf | 3 |
What stands out
Of the 7 model years of Nissan Leaf we track for powertrain problems, this one carries the most owner complaints on file — 12.
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.
CLICKING NOISE FROM FRONT OR REAR AXLE DURING TAKE-OFF/ACCELERATION This bulletin has been amended. See AMENDMENT HISTORY on the last page. Please discard previous versions of this bulletin.
full bulletin at NHTSA ↗PREVENT FRONT AXLE THREAD DAMAGE DURING NUT REMOVAL This bulletin has been amended. See AMENDMENT HISTORY on the last page. Please discard previous versions of this bulletin.
full bulletin at NHTSA ↗DRIVE SHAFT BOOT SERVICE INFORMATION SERVICE INFORMATION If a Drive Shaft (Axle Shaft) Boot on an APPLIED VEHICLE is found to be leaking grease, AND There is no abnormal noise or obvious CV Joint risk due to water intrusion and/or complete grease loss, check for REPAIR KIT-DUST BOOT (CV Joint Boot Kit) availability. ï· If there is a REPAIR KIT-DUST BOOT (CV Joint Boot Kit) available for the vehicle being repaired, do NOT replace the axle. Install a new boot kit following the procedure in the ESM. o Refer to the ESM: TRANSMISSION & DRIVELINE > FRONT AXLE > REMOVAL AND INSTALLATION > FRONT DRIVE SHAFT BOOT o If the complete axle (drive shaft) is replaced when only a new boot is required, the
full bulletin at NHTSA ↗CLICKING NOISE FROM FRONT OR REAR AXLE DURING TAKE-OFF/ACCELERATION This bulletin has been amended. See AMENDMENT HISTORY on the last page. Please discard previous versions of this bulletin.
full bulletin at NHTSA ↗Source: NHTSA manufacturer communications. Bring the bulletin number to your dealer or shop.
The failure pattern owners describe
The dominant issue across these 11 complaints is Nissan's unresolved safety recall 24V-700 (also called R24B2). The recall warns that the traction battery can overheat and catch fire during DC fast charging; Nissan's response was to disable fast charging altogether rather than fix the root cause. Owners say Nissan has repeatedly missed remedy deadlines—first November 2024, then March 2025, now Q3 2025—leaving them without a key advertised feature for over a year. Fast charging is not a luxury for EV owners; it's essential for any trip longer than one charge and for rural or emergency travel. Without it, these Leafs become impractical.
Beyond the recall stall, owners report a serious battery defect: one vehicle experienced sudden capacity loss and entered limp mode at 42,700 miles, with the dealer diagnosing defective cells requiring full battery replacement. Another owner reports uncontrolled acceleration and loss of braking authority while rocking the vehicle on ice—the motor accelerated without pedal input and wouldn't stop unless the brake was held continuously. A third describes increasing clicking noises from the drivetrain during shifting and acceleration. One vehicle even entered limp mode three days after Nissan performed initial recall work, suggesting the remedy procedure itself may be problematic.
Same Nissan Leaf powertrain reports on nearby years: 2019
Failure modes owners describe
DC Fast Charging (CHAdeMO) Disabled - Recall 24V-700 / R24B2
Nissan issued a safety recall (24V-700, referenced as R24B2) warning that the traction battery can overheat and pose a fire risk during DC fast charging. As a result, fast charging capability has been disabled on affected 2020 Leaf vehicles. Nissan has announced multiple remedy timelines (November 2024, March 2025, now Q3 2025) but has not delivered a permanent fix. Owners report the defect renders the vehicle impractical for long-distance travel, which fast charging was a key advertised feature to support.
When: Recall issued approximately 1+ year before complaints filed; affecting vehicles from early production runs
Symptoms owners cite: DC fast charging (CHAdeMO) port disabled; Fire hazard concern due to battery overheating during fast charging; Unable to conduct long-distance travel without fast charging; Vehicle advertised feature (fast charging) unavailable
Codes mentioned: Recall 24V-700, Recall R24B2
Repairs/costs cited: Nissan remedy status as of Aug 2025: still 'developing remedy plan' with expected availability by Q3 2025. No interim solutions, loaner vehicles, or compensation offered to owners.
Recalls/TSBs owners mention: Recall 24V-700 / R24B2 issued; multiple remedy date announcements (Oct 2024, Nov 2024, Mar 2025, Q3 2025) with delays. Initial remedy procedure (P5A22) noted in one complaint, but no final fix deployed. No customer assistance or compensation program mentioned.
Rapid Battery Capacity Loss / Defective Battery Cells
At least one owner reported sudden and severe loss of battery capacity under normal driving conditions (80°F ambient), causing the vehicle to enter 'turtle mode' (limp-home mode). Nissan dealer diagnostics identified one or more defective cells in the traction battery pack, recommending full battery replacement. Vehicle became inoperable. The owner suspects a connection to the DC fast charging defect (recall 24V-700), though this particular vehicle had minimal fast charging history (mostly Level 1/Level 2 charging).
When: ~42,700 miles; incident occurred Nov 5, 2025
Symptoms owners cite: Rapid loss of battery capacity under normal driving; Vehicle entered 'turtle mode' (reduced power mode); Loss of usable range; Vehicle became inoperable
Codes mentioned: Recall 24V-700 (suspected connection), Defective traction battery cells (dealer diagnosis)
Repairs/costs cited: Dealer recommended full traction battery pack replacement. No loaner vehicle provided. No timeline given for repair/replacement. Vehicle remained inoperable at time of complaint.
Recalls/TSBs owners mention: Nissan customer assistance contacted; dealer and Nissan refused loaner vehicle. No remedy timeline offered.
Motor Acceleration Without Pedal Input / Loss of Braking Authority
While attempting to rock the vehicle forward and backward on icy pavement, the motor accelerated without the accelerator pedal being pressed and would not stop when the brake pedal was pressed and released. The vehicle only stopped when the brake pedal was held down continuously. This represents a potential loss of normal braking authority and uncontrolled acceleration.
When: Incident on icy pavement; timing relative to vehicle age not specified
Symptoms owners cite: Uncontrolled motor acceleration without pedal input; Brake pedal press-and-release did not stop vehicle; Vehicle only stopped when brake held depressed continuously; Occurred while rocking vehicle on icy surface
Repairs/costs cited: Owner provided video documentation (not yet uploaded to NHTSA system).
Transmission/Drivetrain Clicking Noise During Mode Shifts and Acceleration/Deceleration
Owner reports loud clicking sounds originating from the transmission/drivetrain area when shifting from Park to Drive, Drive to Park, Park to Reverse, during acceleration, and during deceleration. Clicking began a few months prior to complaint and has been increasing in loudness.
When: Noticed several months before complaint; progressive worsening
Symptoms owners cite: Clicking sound audible with windows closed when shifting modes; Clicking during acceleration; Clicking during deceleration; Progressive increase in loudness
Post-Recall Service 'Turtle Mode' / 'Service EV System Power Reduced' Error
After a Nissan dealer performed an initial remedy procedure (P5A22) related to recall R24B2 on 10/24/2025, the vehicle subsequently entered 'turtle mode' (limp-home mode) with a 'Service EV System Power Reduced' error message during normal driving on 10/27/2025. This suggests the recall remedy procedure may not have resolved the underlying powertrain issue or may have introduced a new fault.
When: 3 days after recall remedy work (10/27/2025)
Symptoms owners cite: Dramatic slowdown / limp-home mode ('turtle mode'); Service EV System Power Reduced error message; Occurred immediately after recall remedy service
Codes mentioned: Service EV System Power Reduced
Repairs/costs cited: Initial remedy procedure (P5A22) performed to address R24B2; vehicle experienced powertrain degradation shortly after.
Recalls/TSBs owners mention: Initial remedy procedure P5A22 performed for recall R24B2; outcome unclear as vehicle failed shortly after.
Synthesized from 12 NHTSA owner complaints — unverified consumer allegations, summarized for patterns. The verbatim filings appear below.
What owners are reporting 1 most recent
On November 5, 2025 our 2020 Nissan LEAF (42,701 miles) experienced rapid loss of battery capacity under normal driving/temperatures (80F.) Vehicle defaulted to "turtle mode" temporarily, an unsafe condition. Were able to replicate condition on subsequent days. Took vehicle to Cedar Park Nissan for evaluation. Technicians concluded that the traction battery had one or more defective cells and…
Had powertrain trouble with your 2020 Nissan Leaf?
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 2020 Nissan Leaf?
It's a documented issue but not catastrophic. 12 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?
Mileage data is limited for this issue. Owners report failures across a wide range, suggesting cause is more about driving conditions and maintenance than mileage alone.
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/2020/Nissan/Leaf.
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.