somefun

I have had the 2016 W205 C300 for six months now and I have encountered two issues that would like to solicit your help with.

1. The proximity key does not work more often than not. I have the key in my pant pocket and when I get close to the driver side door, most time the doors won't unlock themselves. And I have to manually open the doors with the key which is a nuisance.

2. I'm in Canada and when I drive the C300 in deep snow, when the LSD light came on, the car will lose power for a split second. If I press on the gas pedal at that time, the engine does nothing, like power or fuel has been cut off.

After the split second (probably closer to a second in most cases), the car will go back to normal. It almost feels like the car needs the split second to engage the AWD. But I have never encounter a AWD that behaves this way. Do you know what is wrong in my case?

Thank you for your help.

Hapa88

For #2, I think you're referring to the ESP (Electronic Stability Program) and ETS (Electronic Traction Control) systems intervening.

Driving in deep snow, the car is probably detecting wheel slippage when you accelerate and intervenes by reducing power to regain traction.

The 4matic system is an All Wheel Drive system (AWD) where all 4 wheels are permanently driven. It is engaged all the time. What you're experiencing is the ETS system engaging which reduces power to help regain traction.

Per the Owner's manual:
"ESP® monitors driving stability and traction, i.e. power transmission between the tires and the road surface.
If ESP® detects that the vehicle is deviating from the direction desired by the driver, one or more wheels are braked to stabilize the vehicle. The engine output is also modified to keep the vehicle on the desired course within physical limits.
ESP® assists the driver when pulling away on wet or slippery roads. ESP® can also stabilize the vehicle during braking."

"ETS traction control is part of ESP®. On vehicles with 4MATIC, 4ETS is part of ESP®.
Traction control brakes the drive wheels individually if they spin. This enables you to pull
away and accelerate on slippery surfaces, for example if the road surface is slippery on one side. In addition, more drive torque is transferred to the wheel or wheels with traction.
Traction control remains active, even if you deactivate ESP®."

Hapa88

For #1, have you tried the 2nd Key (in the USA, cars come with 2 fully functional keys) to see if that's a problem?

somefun

Thanks, Hapa88.

I have two Mercede keys and they both work intermittently in terms of proximity entry detection. I will ask the dealer to look at this issue the next time I bring my car in.

And yes, it does feel like ESP was engaged when I have bad wheel spin in deep snow. Essentially power is cut momentarily. Thanks for the info.

StanNH

Do the doors unlock when you touch the inside surface of a door handle?

somefun

No, they don't. I've tried that when the proximity function won't work and touching the door handle on the driver's side door does nothing. But sometimes, the proximity function will just work when I approach the car.

Matts2015c300

Are you locking the door with the key or on the door handle? When I use the key to lock the doors I have the habit of hitting the lock button twice which in our cars disables the keyless go system. I know it's a long shot but it would be nice for you if the solution was that simple.

somefun

Well, I never lock the door with the door handle but I do always lock the car but pressing the lock button on the remote. Perhaps I have pressed it twice on occasion and the proximity function won't work? I'll give it a try but this is a good tip, thanks.

Hapa88

Good point! See page 82 where it talks about it.
https://www.mbusa.com/vcm/MB/Digital...16_C_Sedan.pdf

somefun

Ah, this must be the answer to my dilemma. Thanks.