Most likely it's a seized caliper. This would not cause a malfunction light to come on. Your rotor may or may not be warped. I'd be surprised if the wheel bearing was damaged; if it is it will let you know. I haven't experienced brake trouble on my ML.

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Lenny

There are only three sports: bullfighting, motor racing and mountaineering; all the rest are merely games. --Ernest Hemingway

'10 GL550/'04 BMW 545/'99 BMW 323/'98 ML320/'87 VW GTI (race)