2018 Nissan Leaf: What to check before buying

The car suddenly loses drive power. Warnings fill the dash, the car drops into neutral, and messages such as "Service EV System" or "Power supply failure" appear, sometimes at freeway speed. Other reports describe fast battery drain, erratic charge readings, bloated cells, and internal shorts in the high-voltage pack. Some of these failures happen in replacement packs. Cold weather can trigger limp mode or a no-start. One crash report describes losing brakes along with power. Less common faults include PTC heater and A/C compressor failure that disables defrost, plus a touchscreen that locks up.

Most reports describe phantom braking. The car brakes hard on its own with no traffic around, at speeds from about 30 mph up to highway speed, often with automatic emergency braking warnings on the dash. Other reports describe the opposite: braking that is missing or delayed. This happens with e-Pedal on, at a stop, during tight parking-lot turns, or over bumps, where the pedal drops and braking returns after a second or two. Two complaints involve crashes, including a car that crept forward at a light while the driver pressed the brake.

The main concern is unintended acceleration at low speed, and four of the nine complaints involve crashes. Drivers describe the car surging while parking or turning into a driveway, often with e-Pedal on, and not stopping despite hard braking. Cars ended up hitting a pole, a garage, a tree, and a structure. Other reports describe the car lunging with cruise control on, accelerating after the pedal is released, or coasting when e-Pedal regenerative braking fails to engage. A few mention flashing emergency braking warnings or collision avoidance that releases the brakes too early.

Two problems dominate. The steering wheel surface chips, warps, or comes loose, and two owners report cut fingers, one needing urgent care. ProPilot Assist complaints describe the car accelerating toward a stopped vehicle in stop-and-go traffic, or not detecting it at all, so the driver must brake to avoid a crash. A separate report cites an airbag fault light that comes back after dealer resets.

The most common complaint is a front driver door that sags and stops closing properly. Dealer adjustments to the striker or hinge do not last. One report describes a front subframe so rusted it failed inspection at 27,599 miles. Another describes B-pillar plastic door trim that looks melted by reflected sunlight, which the dealer refused to cover as a defect. None of these reports involve a crash or injury.

The main pattern is faulty front passenger occupancy sensors. The seatbelt or airbag warning light stays on with the seat empty, and the passenger airbag status light can stay lit with someone seated. Dealer code clears fix it for only a month or two. One quote to replace two sensors came to $1800. In a separate crash report, the air bags did not deploy when the car was hit from behind and slid into a curb.

The car shuts down or loses power, and the reports trace this to the high-voltage battery. Owners describe the car shutting off at highway speed while climbing, diagnostics showing bad cells in the main battery, and the charge falling from about 60% to 25% within seconds in cold weather. One fire-related report starts with a "Service EV System No Power" no-start at 29,862 miles. A thermal event involving the Power Distribution Module followed.

A malfunction warning appears and automatic emergency braking stops working. Dealers trace it to a failed front radar or sensor, which also disables cruise control. One failure comes at around 25000 miles, and one repair quote is $1900. Neither complaint describes a crash. Both describe a system that has shut itself off and costs a lot to restore.