General Motors has issued a stop sale for select Cadillac CTS models that could shut off while moving if the driver's knee bumps the ignition key.

Affecting 2003-'14 CTS and 2004-'06 SRX vehicles, the stop-sale order is because GM doesn't yet have a solution for certain Cadillac models with problematic ignition switches, Reuters reported over the weekend.

The recall, which is only the latest in a record year for GM, affects around 554,000 Cadillacs in the U.S. The automaker has recalled around 14.7 million vehicles for faulty ignition switches that can turn off the car and disable the air bags.

A 2.6 million-vehicle recall of various GM small car models earlier this year has been connected with at least 54 crashes and 13 deaths. Since the announcement, the automaker has been urging owners to remove everything except the necessary key from their key rings.

The SRX and older versions of the CTS are plagued with switches that can turn off if the key ring is too heavy or gets jarred, moving the ignition out of the "run" position, according to GM documents provided to federal regulators.

For the revamped 2014 CTS, Cadillac is changing to a push-button starter switch.

The affected SRX and CTS vehicles will get a new key that has a small hole instead of a slot, a change that GM says will keep the key more firmly in place. But the second-generation CTS vehicles from model years 2008-'14 pose a trickier problem since they still have a tendency to switch off unexpectedly even after GM started putting small-hole key in the vehicles in late 2010.

Various GM models have long been plagued with ignition switch problems, some of which apparently came to light around a decade ago.

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