Topic: Merceds 2003 SLK320 Braking Problem

[colton]

My 2003 Mercedes SLK 320 stops suddenly on its own.  This is an intermitant problem that happens about once or twice a week.  When the brakes are applied, even softly, the brake assist kicks in and brings the car to a sudden halt, then releases.  There are no codes, this is not the transmission gearing down, and the brakes are applied evenly.  The brake pedal goes down on its own after the initial pressure.  Twice, I have almost been hit from behind.  An article in "Canadian Driver" lauds Mercedes for this system, but it can be very dangerous.  The article says that the system learns how the driver usually brakes, then identifies "emergency situations" and applies the brakes, full force, on its own in these situations.  Does the system recognize different drivers?  The dealership says that with no codes and not being able to duplicate the event, they cannot fix.  Anyone have any
suggestions?

[maritime_storm]

See your local dealer, you don't want to cause an accident. Mercedes isn't exactly known for stellar reliability of their electronics.

[Careener]

I found this suggestion on another site.

http://www.justanswer.com/questions/2p8wl-my-2003-slk320-has-32k-miles-and-has-recently-began-to

Question

My 2003 slk320 benz has 32k miles and has recently began to stop abruptly and then start to go almost immediately after. It's like you're driving 40mph and then you slam into an almost complete stop and then start driving again at about 10mph. It has happened to my husband once as he was starting to apply the brakes and once to myself while driving (w/o applying brakes). It's like the car is braking suddenly and abruptly on its own. Do you possibly know what might be the problem...maybe the brake assist? Thank you.
Submitted: 76 days and 1 hours ago.

Category: Mercedes Value: $15 Status: CLOSED +Read More
Accepted Answer

Hi,

It is a possibility however the BAS system rarely causes problems.

I would still have the vehicle checked for any fault codes as there may be something stored to go on.

If there is no fault codes I would try disconnecting the electrical connectors the plug into the brake servo under the hood. There is a travel sensor for measuring brake pedal movement for BAS & the solenoid inside the servo for engaging BAS. Then try the vehicle with these disconnected. It will put warning lights on the dash that will need clearing after testing however.

Also inspect the brakes for signs of binding & overheating - ensure the brake pads are free to move in the calipers & is not the brakes binding up.

Let me know how you get on.

Best regards, XXXX

[johngenx]

Yup, BAS system failure.  It is supposed to fail to "non functioning" but with MB's electronics, who knows what might happen.  2000-2005 were abysmal years for MB quality.

BAS is "brake assist system."  It sense emergency braking and applies the brakes with to-ABS force to compensate for driver hesitation.  Great system, and now used by most everyone (even our lowly Corolla has BAS now), but it sounds like the BAS in your SLK has failed.  Good luck, as these systems can be $$$ to repair.

[HeliDriver]

Yup, BAS system failure.  It is supposed to fail to "non functioning" but with MB's electronics, who knows what might happen.  2000-2005 were abysmal years for MB quality.

BAS is "brake assist system."  It sense emergency braking and applies the brakes with to-ABS force to compensate for driver hesitation.  Great system, and now used by most everyone (even our lowly Corolla has BAS now), but it sounds like the BAS in your SLK has failed.  Good luck, as these systems can be $$$ to repair.

You make it sound so mundane.

If it's that common for an MB electronic brake system to fail, causing the car to slam on its brakes uncommanded by the driver, why is it so unbelievable for the electronic throttle on a Toyota to do likewise?   

[inco]

Yup, BAS system failure.  It is supposed to fail to "non functioning" but with MB's electronics, who knows what might happen.  2000-2005 were abysmal years for MB quality.

BAS is "brake assist system."  It sense emergency braking and applies the brakes with to-ABS force to compensate for driver hesitation.  Great system, and now used by most everyone (even our lowly Corolla has BAS now), but it sounds like the BAS in your SLK has failed.  Good luck, as these systems can be $$$ to repair.

You make it sound so mundane.

If it's that common for an MB electronic brake system to fail, causing the car to slam on its brakes uncommanded by the driver, why is it so unbelievable for the electronic throttle on a Toyota to do likewise?   

So maybe the battle of Alberta is not just confined to hockey and fooltball? 

[No H2O]

Anyone have any suggestions?

Contact the government agency that deals with vehicle safety defects. If a system fails, then it should at least revert to a basic operating system and not brake all by itself.

There is nothing like a simple master cylinder connected to calipers and wheel cylinders via simple tubes and hoses. Works so well. High tech...