UPDATED: See below.
According to a report in the New York Times, BMW is issuing a major recall for 5-Series sedans and wagons and 6-Series sedans and convertibles from the 2004 - 2010 model years.
Although the National Highway Traffic Safety Administration hasn't yet posted a notice about the recall to its website, the Times reports that the problem stems from a dodgy battery cable connection that sits in the vehicles' trunks.
Apparently, one of the bolts holding that connection in place can loosen over time. As a result, resistance can build up in the electrical cables, which can cause the cable connections to overheat. This, in turn, can result in electrical system problems, or in some cases, smoldering of the trunk mat.
A BMW official acknowledges that the flaw has caused at least one fire in the U.S., though no injuries have been reported.
What's interesting is that the recall appears to come from BMW itself, not from a NHTSA investigation. Approximately 1.3 million vehicles are affected worldwide, 367,000 of which are located in the U.S.
We'll update this post when we have NHTSA's official details about the roll-out of the recall and proposed remedies. If you have questions in the meantime, we encourage you to contact BMW customer relations at 800-525-7417. Stay tuned.
UPDATE: NHTSA posted the official BMW recall bulletin this morning, and it's now clear that the M5 and M6 are both included in the recall. As it stands, the affected BMW models are:
The total number of U.S. vehicles included in the recall stands at 367,682.
As far as the rationale for the recall, NHTSA's bulletin clarifies that "The insulated bulkhead connector for the positive battery cable may have been incorrectly attached to the trunk floor panel, which can lead to a loosening of the bolt connection." That, in turn, can cause the overheating described above.
It's very important to note that NHTSA says this overheating can occur even when the vehicle is not in use. As a result, NHTSA encourages owners to park their vehicles outside until the problem is fixed.
BMW will begin sending out notices of the recall in April. At that time, owners will be able to take their vehicles to a local dealer, who will inspect and replace the battery bolt cable connection as necessary, free of charge.
If you own one of the affected vehicles and have additional questions, you can call BMW customer relations at the number provided above, or ring NHTSA at 888-327-4236 and ask about recall campaign #12V126000.