Brake light warning.

[Don Z.]

"Check Left Brake Light" warning message lights up on the dash. Seems an easy fix, right? Replace the bulbs.

Replacement is a P21 4 watt bulb. Not 5 watts, 4. I made sure I got that part right. All fuses are good. All bulbs work as designed.

And the warning message is still on. Am I missing something? Is there a Durametic dance I need to do to reset the light?

I've checked power to the fixture. I can see the bulb goes on when you step on the brake, and off when you're not on the brake. Everything seems to be correct, and still there is the warning message.

Is there another sensor/relay I can check?