"We do not believe this problem exists in any other car outside of Fiat Chrysler," Harman Chief Executive Dinesh Paliwal said in an interview with Reuters on Tuesday.
Harman Kardon-branded infotainment products are part of Fiat Chrysler's Internet-connected Uconnect telematics system, a collection of driver aids and entertainment services.
Two veteran cyber-security researchers recently used a software vulnerability in Uconnect to break into a Jeep Cherokee being driven on the highway, intensifying the debate about the safety of increasingly connected cars and trucks.
Fiat Chrysler, working with Harman, has issued a software update for the recalled vehicles and has provided customers with additional software to improve security.
Uconnect also uses software and network connectivity provided by other companies.
"Our system was safe and secure," Paliwal said, adding that the issue apparently started due to a "hole" or port opening in a network. "Once you leave the door of the house open, somebody will walk in and they can do whatever they want," he said.
Fiat Chrysler declined to comment.
Paliwal said Harman did not anticipate any financial impact related to the recall.
Apart from Fiat Chysler, Harman's customers for infotainment systems include BMW, Daimler and Volvo among many others.
© Thomson Reuters 2015