Mr. Musk has often been accused of exaggerating the software’s abilities and making overly optimistic predictions about when it will be able to drive a car from one location to another without human intervention. Despite the names Autopilot and Full Self-Driving, the company’s software requires drivers to remain engaged and be prepared to assume full control of the vehicle at a moment’s notice.

The California lawsuit was filed by Lindsay Molander and her son, Parker Austin. In June 2019, they were passengers in a Tesla Model 3 car driven by Micah Lee, who died after the car suddenly veered off a highway, smashed into a palm tree and burst into flames. Ms. Molander and her son were severely injured.

They blamed a malfunction by the car’s driver-assistance software for the crash. During closing arguments in the trial, Jonathan Michaels, who is representing Ms. Molander and her son, cited Tesla internal documents, which he said showed the company was aware of a defect in the software that could cause the car to veer suddenly.

Lawyers for Tesla argued that human error was to blame. The software was not capable of causing the car to veer as suddenly as it had in the accident, Michael Carey, a lawyer representing Tesla, told jurors during closing arguments in the trial.

Mr. Carey blamed Mr. Lee, who had consumed several drinks at a restaurant and shopping district near Disneyland in Anaheim, Calif., with Ms. Molander. Mr. Lee had alcohol in his blood, according to tests conducted several hours after the accident, but not enough to be considered intoxicated under California law.