Sarlox

Has anyone experienced an occasional 2X the normal cycle rate (ticks twice as fast as normal) on your front turn indicators, then you get a trouble warning on your display that says something about a bad light bulb?

When I turn the car off and back on, it goes away. Used to be just the right side, now the left side is starting to do it. Not all the time. I would say 1 in 100 times.

pdeacon

The rapid blinking usually indicates there is a bad bulb in the circuit. If the front signals are flashing rapidly replace the rear turn signal bulbs. Sometimes you can't tell whether the bulb is good just by looking at it. If you replace the bulbs and the problem persists you may have a short in the circuit. Good luck troubleshooting.

Sarlox

If the fronts are the ones flashing rapidly, why replace the rears?

pdeacon

If it were the fronts they wouldn't light at all. You can try turning the key to the on position and walking around the truck with the turn signals on. Hopefully it's just a bulb. Electrical shorts can be a real pain. In older vehicles it could be bad grounds or corroded connections but I see your vehicles are fairly new. Let's try the easy stuff first.

AMGRay

I don't speak Mercedes but this is the way things was done with domestic vehicles for years. A rapid blinker light was a clear indicator that the opposite light bulb was bad...front or rear. Example, if the front right indicator was blinking rapidly, the rear right indicator bulb was usually burnt out. I don't know how this translates to LEDs or Mercedes however.

pdeacon

Same principal applies to MB and LED's.

drew138

Possible related to the fog lights?

gurukid

As pdeacon suggested, check both front and rear of the side that blinks faster. Also check your side indicator. If any lights on the circuit are bad or shorted, this will happen. Either way, if it's the front or rear blinker, it's a 2 minute job to replace.

Copple

We have a 2015 G550 that's exhibiting the same problems. Randomly we'll get the 2x flashing front turn signal along with a dash warning of a bad bulb. Did the original poster ever get any resolution? Our dealer is saying we need to replace the turn signal gasket but I feel like its something else as it's something that happens so sporadically. It also resets when you switch off the car and turn back on.

streborx

Sometimes a bit corrosion on the bulb or socket contacts is all it takes to cause intermittent behavior. Get a can of electrical contact cleaner or use some CLR on a Q-tip and rub off the oxidation. If one bulb is flakey they all might be in need of cleaning.