I've noticed on cars with LED tail lights that they have a flicker to them - I presume because they're PWM controlled.
But I've seen it on vehicles where brake lights and tail lights are separate luminaires, therefore are just on or off and do not have varying brightness. I understand that LEDs need to have current through them limited, but I don't see how PWM would achieve this?

Edit: bad phrasing - sorry. Better phrasing: why would the LEDs be flickering even though there is no apparent feature to allow changing of the brightness? Perhaps the brightness is factory set, or maybe there is a feedback circuit to keep brightness constant. But could there be any other reason?

Thoughts: because a vehicle's battery has a significantly different voltage across it when the engine is off or on, (12v vs 14.5v) perhaps there is a controlling PWM circuit that keeps brightness constant over a range of voltages. Saying that, I'm convinced that smart phone screen back-lights have some flicker to them even on full brightness, yet their Li-ion batteries' voltages are near constant.


Question: Where should issues with Google Play Services (e.g., fused location provider) be reported?
Answer: Then post your question where it's sure to be seen: googleplus help. That link is, after all, one of the few links the closed page offers with any actual developer interaction. I looked, and saw many questions were way off-topic, but the questioners were usually led to the right forum, or had their question answered. And you can always point back to the "closed forum" page you referenced as your reason for being there. You have a legitimate question; let them know that, the only way that seems possible!