SmokinBuddha

Lately there's a red light that comes on and disappearing very quickly with a beep, I don't know which light that comes on and disappear. Then yesterday while driving on the highway, I was exiting the ramp to go on another highway when all of the sudden my car slammed on the brakes. Lucky I was only driving around 20 mph and the car behind me didn't hit me. Things could had been worse, if I was driving faster. Anybody else is experiencing this issue with their GLC43?

oilman4345

Very possibly the "proximity" warning light which comes on with a sound when you are too close to vehicle in front.
As far as the braking, you may have the automated collision avoidance (I do not on my 43).

viper3ez

I agree, sounds like the collision avoidance which works together with the proximity sensor.

I have several cars with that system so I have learned to deal with it by staying on the gas through the braking.

it's basically a negtive feature off all emergency braking systems.

SmokinBuddha

But the way I was driving the sensor shouldn't had come on at all. Once I was at a complete stop on the highway, I press down on the gas pedal and the car suddenly stopped with force, like someone slammed on the brake. Thanks for all the replies, but I made an appointment to bring my car into the service dept. on Saturday.

scotchy

Yeah it sounds like its acting up/faulty.
There's a steep ramp that will make mine go off if I descend it too fast, I don't know if it thinks the flat road at the bottom is something you might hit or what the deal is. It doesn't do it if you're going really slow but even at a normal speed down the ramp it'll beep and brake...it's quite unnerving when it's not needed but is good if you're driving and not paying attention and the car in front of you slams its brakes on or something.
Hopefully they can sort it without issue!