The 2002 Honda Civic EX is one of the models covered by the expanded Takata airbag recall.

Honda will voluntarily recall about 5.4 million vehicles nationwide to fix potentially defective Takata airbags – about 10% fewer cars and crossovers than the maker had originally signaled when it announced the safety campaign last week.

More than 2.8 million of those vehicles were already covered by a recall Honda announced last June, and the maker says many of them have already had their airbags replaced. They will not need additional repairs.

Honda is the single largest customer for airbags produced by embattled supplier Takata. The Japanese parts manufacturer last week told members of a Senate committee it would not expand an earlier, regional recall for faulty airbags. But Honda and several other automakers have decided to expand the safety campaign on their own.

When Honda first announced the expanded recall, a senior official estimated it would cover about 6 million vehicles. Spokesman Chris Martin said that after a closer inspection, Honda realized the total population of vehicles equipped with the suspect airbags would be the slightly 5.4 million announced today.

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The controversy surrounds vehicles using Takata airbags produced in two North American plants. Evidence indicates that under certain conditions they can over-inflate when triggered during a crash. That can cause metal fragments to shoot into the passenger compartment, a situation so far linked to at least five deaths in the United States and a number of injuries.

Initially, Takata said its studies showed the airbags were susceptible to the high humidity conditions in Florida and other parts of the country. That led the National Highway Traffic Safety Administration to order a regional recall in October covering 7.8 million vehicles.

Since then, however, there has been mounting evidence that the Takata bags might fail in other parts of the country. NHTSA has been pressing the Japanese supplier to expand the recall for driver’s side airbags to cover all vehicles sold in the U.S. with the suspect systems. It continues to study whether passenger-side bags might also need repair.

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During a Senate hearing last week, a senior Takata official said the company saw “no evidence to justify the expanded action and declined to add more vehicles to the recall. But Honda decided to act on its own – in part, after having come under fire for previously failing to report all airbag failures to federal regulators as required by law.

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The maker, along with Toyota, has called for an industry-wide study of the Takata problem.

“Honda hopes that the expansion of this action nationwide will both address customer concerns and further assist in the ongoing industry investigation of abnormal airbag deployments in the vehicles from all affected manufacturers,” the company said in a Monday afternoon statement.

Honda now will include this list of vehicles in its recall:

• 2001-2007 Honda Accord with 4-cylinder engines
• 2001-2002 Honda Accord  with V6 engines
• 2001-2005 Honda Civic
• 2002-2006 Honda CR-V
• 2003-2011 Honda Element
• 2002-2004 Honda Odyssey
• 2003-2007 Honda Pilot
• 2006 Honda Ridgeline
• 2003-2006 Acura MDX
• 2002-2003 Acura TL
• 2002 Acura CL

Owners can find more information by going to www.recalls.honda.com and www.recalls.acura.com or by calling (800) 999-1009 for Honda owners or (800) 382-2238 for Acura owners, and selecting option 4.