Honda has admitted to failing to notify US safety regulators of 1,729 claims of injuries and deaths related to accidents in its vehicles since 2003.
Honda's US arm was responding to a 3 November order from the National Highway Traffic Safety Administration (NHTSA), seeking an explanation for why Honda failed to fulfil its legal obligation to report deaths and injuries, especially those involving airbags, as an investigation into deadly defects in Takata airbags used by the firm continues.
The Japanese automaker said in a statement that its count of underreported claims came from a third-party audit, blaming "various errors related to data entry" and an "overly narrow interpretation" of its legal reporting requirements for the omission. It said it is taking steps to remedy these shortcomings.
"I haven't got a detailed report yet, but it seems there were a lot of administrative mistakes on the ground," Honda CEO Takanobu Ito told reporters at a corporate event in southern Japan.
Since 2008, Honda has so far recalled more than 7.5 million US cars because of defects found in inflators in some Takata airbags that cause them to rupture, spraying metal shards into the vehicle cabin.
NHTSA sent a second order to Honda on 5 November seeking details and documents related to the airbags and inflators.
Honda sent its response on Monday to NHTSA's first order. A summary of that response was read out by Rick Schostek, executive vice president of Honda North America, on a conference call with reporters, though he declined to take questions. Schostek testified last week at a US Senate Commerce Committee hearing on Takata airbags.
In the 'early warning' reporting data required by US law, Honda failed to disclose eight incidents of ruptured Takata inflators that resulted in one death and seven injuries, Schostek said. The company said it provided details of those incidents to NHTSA outside the 'early warning' reporting process.
Japanese Transport Minister Akihiro Ohta said today that his ministry set up a task force late last week to deal specifically with Takata's recalls. The ministry is also looking into whether Honda underreported incidents in Japan, an official said.
Separately on Monday, a lawsuit was filed in South Carolina federal court linking a Takata airbag to the 2008 death of Mary Lyon Wolfe in a 2002 Honda Accord. The lawsuit said the airbag in Wolfe's car "deployed with excessive force" and caused grave injuries. Wolfe died 18 days later from her injuries, it noted.
A Takata spokesman declined to comment. A Honda spokesman said the company had not yet been served with a copy of the lawsuit and declined to comment on its specifics.
Also on Monday, the Senate requested additional airbag-related documents from Takata "to gather information that could address questions left unanswered" at last week's hearing.