Car says the right-rear turn signal is malfunctioning, and the right side is flashing quickly. Yet all three bulbs (headlight assembly, side scuttle, and taillight) are functioning normally - other than the fast-flash.

What gives? Everything is stock and original. Anyone else seen this?

 

I figured this out. It was the inner bulb on the bumper, you know, the one that never comes on.

 

That's for rear fogs, yes?
If so, do you have them, or is the bulb just there?

 

No, the rear fogs are on the side of the big cluster on the barn doors. I have coded them to work with the brake lights.

The inner bulbs on the bumper were brake lights when I bought the car, but a later recall turned them off. I think they can also be set up to be used for extra brake lights under emergency braking, but that feature doesn't get enabled in US cars.

What they *DO* do is act as a turn signal when your barn doors are open -- my barn doors weren't open, but that bulb's failure was enough to trigger the brake light failure warning.