The recall storm cloud hanging over GM’s head continues to grow as the automaker recently ordered Cadillac dealers to stop selling its popular CTS and SRX models because it does not have a fix yet for the 554,000 cars recalled in late June.

The most recent Cadillac recall is over an issue where engines can be shut off if the driver’s knee bumps the ignition key. When bumped the key moves out of the “run” position causing the engine to shut off, ultimately disabling the power-assisted steering, brakes and airbags.

While this is similar to the problem that that forced GM to recall over 2.19 million small cars in February and March, the affected Cadillacs do not share the same parts. The GM small car recall is linked to at least 16 deaths in vehicles with switch-related problems, and the automaker knows of at least 61 crashes caused by faulty ignition switches.

GM has halted dealers from selling any recalled Cadillacs on their lots until it comes up with a fix. The latest recalled models include the 2003 to 2014MY CTS, but does not include the recently redesigned CTS four-door sedan. Also recalled are the 2004 to 2006MY SRX crossovers. The recent Cadillac recalls tack onto a running list of over 13 million other GM vehicles recalled this year because of ignition-related issues.

Despite the massive recalls this year, GM new vehicle sales have remained positive. Sales for all of GM’s respective brands improved by 1% in June, and current year-to-date sales for the automaker are up by 2.5% compared to the same period in 2013.