The National Highway Traffic Safety Administration on Thursday opened an audit investigation into whether Tesla Inc. failed to submit crash reports involving its Autopilot and Full Self-Driving systems within the time limits required by federal rules. The agency said it had identified numerous cases in which Tesla’s incident reports arrived "several months or more" after the crashes, despite a Standing General Order that gives manufacturers one to five days to file once they learn of a collision. Tesla told regulators the delays stemmed from a data-collection problem that it says has now been corrected, but the company has not publicly commented. Investigators will examine the causes and extent of the late filings, determine whether any crashes remain unreported, and assess the adequacy of Tesla’s corrective measures. The audit runs alongside broader safety probes covering roughly 2.4 million Tesla vehicles after at least four collisions—one of them fatal—linked to the company’s driver-assistance technology.