General Motors Co. issued a new, separate recall Monday of more than 1.5 million cars for a steering defect, and the company now estimates the recent spate of recalls will cost it about $750 million.

The power steering defect, which covers a range of compact and midsize cars from 2004 through 2010 model years, is not related to the company’s recently expanded ignition-switch recall – but some of the vehicles affected by the new recall are also affected by the ignition switch issue.

Collectively, the recalls reflect a series of quality problems that threaten to distract consumers not long after the automaker was celebrating a series of product awards and its escape from government ownership.

GM did not immediately disclose whether the power steering defect caused any deaths, but a quick review of complaints filed with the National Highway Transportation Safety Administration showed some crashes and injuries.

The new recall comes a day before GM CEO Mary Barra is expected to testify before Congress about the company’s failure to fix the faulty ignition switches.

“With these safety recalls and lifetime warranties, we are going after every car that might have this problem, and we are going to make it right,” said Jeff Boyer, GM’s newly appointed vice president of global vehicle safety. “We have recalled some of these vehicles before for the same issue and offered extended warranties on others, but we did not do enough.”

The new recall affects:

• All Chevrolet Malibu models from 2004 and 2005 and some from 2006, 2008 and 2009, as well as all 2004, 2005 and some 2006 Malibu Maxx models.

• All Saturn Ions from 2005 through 2007, vehicles that are also caught up in the ignition switch crisis.

• All 2005 Pontiac G6 models, as well as some from 2006, 2008 and 2009.

• All 2008 and 2009 Saturn Auras.

• Some 2010 Chevrolet Cobalt models and some 2009 and 2010 Chevrolet HHR models, which are also involved in the ignition switch recall.

“If power steering assist is lost, a message displays on the Driver Information Center and a chime sounds to inform the driver,” GM said in a release. “Steering control can be maintained because the vehicle will revert to manual steering, but greater driver effort would be required at low vehicle speeds, which could increase the risk of a crash.”

GM said it would make free repairs on the vehicles, which may include replacing the power steering motor, steering column or power steering motor control unit. It said it will reimburse customers who have already paid for repairs.

The company said owners of 309,160 units of the 2006-08 HHRs without turbocharged engines and 96,324 Saturn Ions from the 2003 model year that are not subject to the new recall will receive lifetime warranties for the electronic power steering motor.

Separately on Friday, GM recalled a half-million new pickup trucks and SUVs to fix a transmission problem that could trigger a fire and also recalled about 190,000 units of the Chevrolet Cruze sedan.