DETROIT — The US government has slapped Toyota Motor Corp. with a record $17.4 million fine for failing to quickly report problems to federal regulators and for delaying a safety recall.

The fine from the National Highway Traffic Safety Administration is the maximum allowed by law. It’s the fourth fine levied against Toyota in the past two years for similar infractions, and it’s the largest single fine ever assessed against a car company over safety defects. In 2010, Toyota paid a total of $48.8 million in fines for three violations.