The temporary sales stop includes all new Avalon, Avalon Hybrid, Camry, Camry Hybrid, Corolla, Sienna, Tacoma and Tundra vehicles equipped with seat heaters, the Japanese automaker said.
Toyota said that a small portion of the seat assembly failed to meet a provision of U.S. motor vehicle safety standards requiring materials to retard flame at specified rate.
"Toyota is preparing a modification for this condition, which will be implemented on all covered vehicles in dealer inventory. There have been no reports globally of any related incidents in the field with units in operation," the automaker said in a statement.
Though Toyota is halting sales of the cars to make a fix that will bring them into compliance, at this time, it doesn’t plan to
Toyota said it learned of the problem from South Korean safety regulators who had tested a seat on a U.S. built Camry hybrid. All of the affected vehicles are built in the U.S.
Toyota didn't say what percentage of the vehicles come equipped with seat heaters, but the action includes some of its biggest sellers.
The automaker sold more than 408,000 Camrys last year, making it the bestselling passenger car in the U.S. With sales of more than 300,000, the Corolla also was a popular model.
"This is an issue that if not addressed properly could be hazardous," said Dave Sullivan, manager of product analysis for consulting firm AutoPacific Inc. "This is an electrical current that is going through your seat."
Seat heaters typically come on cars sold with fancier interiors and in cold climates.
"Where I live in Michigan, where recently it has been a negative-15 degrees, heated seats are a very popular option," Sullivan said. "This is definitely going to have an impact on sales."
Sullivan praised Toyota for being "proactive rather than reactive," but he said the automaker needs to give consumers more information about the problem and look at making the same fix in any vehicles already sold that don't meet the safety standard.
"This is a big deal to have a stop sale like this," Sullivan said. "But it is also a big deal to repair all these vehicles. You have to make a kit and ship it to all the dealers and then have all the cars fixed. It will be expensive."
This is the second time that Toyota has halted sales of a large segment of its lineup for a safety issue.
Four years ago, the company briefly stopped sales of eight models -- including the Camry and Corolla -- saying the gas pedals could get stuck and cause runaway acceleration. The automaker also shut down production of the vehicles for a week while it examined how to fix the problem, which it attributed to wear on the pedal system.