General Motors will begin this month to notify car and truck owners of recall notices through its OnStar in-vehicle communications service, the Associated Press (AP) reported.

GM said Wednesday it would contact owners through the onboard system if they fail to bring their vehicles to a dealer for recall repairs within 60 days of receiving an initial notice, the news agency added.

"We want to remind owners that complying with a recall notice is very important," Gay Kent, GM's director of product investigations, told AP. "Recall notices are not junk mail that should be set aside or thrown away."

The Associated Press said 3.5 million owners of GM vehicles subscribe to OnStar, which alerts emergency rescue officials when an air bag deploys or the vehicle is struck in a moderate to severe crash.

Subscribers who press the blue OnStar button during non-emergency service calls will be told of the recall and given the opportunity to connect with a dealer to schedule repairs, the report said.

Kent told AP the reminders are aimed at increasing recall completion rates, which in recent years have ranged from more than 50% to about 98%.

The news agency noted that automakers typically notify owners of a recall by mail and then follow up with postcards every two months.

OnStar spokesman Terry Sullivan told the Associated Press that, as an option, OnStar service costs $US695 - roughly $500 for the hardware and $200 for the first year's subscription fee. After the first year, the subscription price is $16.95 a month and the retention rate for service is more than 60%, he added.