Question about Mercedes-Benz S500

3 Answers

BRAKE LIGHTS STAYS ON. the swith isnt the problem.

Mercedes S500 brake light stays on. I changed the switch and it didnt help. could it be something else.The car also starts without me pressing the break first.

Posted by on

  • 1 more comment 
  • MASE May 24, 2012

    brakelights and tail lights stay on when I start the car and while driving

  • MASE May 25, 2012

    i went to auto mecanic who replaced the switch, But the brake lights still are on.The mecanic also states that the car starts without having your foot on the brakes.if the car is off the brake lights are off, but if the car is on the break lights stays on. What else could it be? please help. could it be a transmitter is so whats is the part name and number. thanks

  • Anonymous Jan 24, 2019

    We see this all the time on W215/W220 models - Brake lamps are on anytime the key is in position '2' -  In STAR/Xentry, it's easy to check the operational status of the brake lamp switch. It is also easy to check the signal status of the Rear SAM. In almost every case, we replace the ESP/PML/BAS control unit and the problem is solved. Leave the key on for 15 minutes. The ESP/PML/BAs control unit will be hot to the touch with this type of failure...



3 Answers

  • Level 2:

    An expert who has achieved level 2 by getting 100 points


    An expert that got 5 achievements.


    An expert who has answered 20 questions.


    An expert that has over 10 points.

  • Expert
  • 35 Answers

This can be a bad relay for brakes, brake signal return wire is short to positive known as ( cold short ) best disconnect the plug from the brake switch use a test lamp and check if you have power on both wires if not your output wire from the relay terminal 87 is short to positive

Feel free to ask fixya

Posted on Jan 24, 2019

  • daniel k nakwafila
    daniel k nakwafila Jan 24, 2019

    This can be a bad relay for brakes, brake signal return wire is short to positive known as ( cold short ) best disconnect the plug from the brake switch use a test lamp and check if you have power on both wires if not your output wire from the relay terminal 87 is short to positive

    Feel free to ask fixya


  • Level 3:

    An expert who has achieved level 3 by getting 1000 points


    An expert that got 10 achievements.


    An expert that got 5 achievements.


    An expert who has answered 1,000 questions.

  • Master
  • 1,573 Answers

You SHOULD be able to start car without depressing brake pedal. Just not shift into gear without brake.

Posted on Jan 24, 2019

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points


    An expert that got 20 achievements.


    An expert that got 10 achievements.


    An expert that got 5 achievements.

  • Mercedes-Benz Master
  • 5,692 Answers

If the car thinks the brakes are on, then the switch on the brake pedal lever under the dash is bad. But this switch is not the only switch you have. IF your system works like the Ford products I am use to, then another interlock is present to prevent you shifting out of Park without pressing the brakes.

If you are able to shift without your foot on the brake, you are still getting a signal to the second interlock with the trans. This means the brake pedal switch is saying your foot is pressing the pedal. Some cars are in the data base for If you can register your car for free, most will have free wiring diagrams and fusebox layouts.

You may have a relay for brake lights on a Mercedes. Other cars usually do not because it affects reliability. But a stuck brake relay could keep the light circuit on, if equipped.

A better scanner can do brake functions and all you need to do is plug in the tester to the ABS port and see if the abs is identifying a problem. The cheaper scanners do not have this feature.

A remote possibility is that you have a bad Master cylinder and the pedal is not returning to the full upright position.

I hope my solution is helpful.

Posted on May 25, 2012

  • Victor
    Victor Sep 27, 2018

    Only my third break light stays on, and the top tail light on the driver side , is on but very dim and is flickering. It will turn off when I unplug it from u see the back seat. Also my s shade goes up on its on ,can anyone help.


3 Suggested Answers

  • 2 Answers


Hi there,
Save hours of searching online or wasting money on unnecessary repairs by talking to a 6YA Expert who can help you resolve this issue over the phone in a minute or two.

Best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.

Here's a link to this great service

Good luck!

Posted on Jan 02, 2017

  • 214 Answers

SOURCE: maintenance light and brake lamp light what does it mean

The Maint Req Light is only a reminder light to get the Oil changed and fluids checked and what nots.. Its on a timer that must be reset.. Its no big deal if ya had it seviced recently.. Heres how to turn it off: 1) Make sure Key is Off 2) Press and Hold Mileage reset button. 3) While Holding Milelage Reset button, swicth car to run, but dont crank..4) Continue to hold button until light flashes and goes off.. then switch it off .. Start the engine to make sure it worked.. Sometimes ya gotta do it twice.. NOW.. And ur Lamp indicator.. Means you probably have a brake light or turn signal bulb out on the rear.. Get someone to help ya look for that.. Lemmie know if this works.. and Take care.. Thanx

Posted on Mar 11, 2009

  • 174 Answers

SOURCE: Brake lights stay on

check the brake light switch on the pedal

Posted on May 24, 2009

Add Your Answer

Uploading: 0%


Complete. Click "Add" to insert your video. Add



Related Questions:

1 Answer

Wht mercedes wont start, tailghts stay on?

The brake light switch is tied to the ignition system.

Check your brake light switch. very common problem.
Follow the brake pedal up until you see it. small electrical part with connection to it.

Make sure to get a "real" Mercedes replacement part, as the aftermarket ones are even flakier than the dealer ones.
They are not that expensive and it's pretty easy to replace yourself.
Hope this helps!

Jul 29, 2014 | 2003 Mercedes-Benz S430

2 Answers


its the brake light switch....have it changed and if that does not solve the issue, check the ground wire to the brake light

May 31, 2014 | 1996 Honda Accord

2 Answers

Brake Lights Problems

try testing switch by brake, could be faulty switch

Apr 28, 2013 | 2006 Mercedes-Benz ML-Class

1 Answer

Brake lights stays on

e-brake may be on part way

Mar 10, 2013 | Cars & Trucks

1 Answer

Why won't my MB ml350 brake lights work even after i install new bulbs?

Did you check the fuse? Either the fuse may be out, or the brake light swith on the brake pedal may be out or need adjusting. You should have 12 volts at the brake switch.

Nov 18, 2011 | Mercedes-Benz Cars & Trucks

1 Answer

2000 mercedes s500 brake light always on

The brake switch is a pressure switch mounted on the brake pedal, master cyclinder output which on pressure will contact and switch the brake lights ON.
So if the brake switch is defective then it must be replaced, check for wiring leads, the ground connection of the brake light assembly.

Sep 29, 2011 | 2001 Mercedes-Benz S-Class

1 Answer

My break light swithes on sometimes without me even pressing the breaks. The break light also sometimes stays on even when I have taken my feet off the break. I have tried changed the break light switch...

Did you adjust the brake light switch correctly? To adjust the brake light switch, first press the brake pedal down a few inches, then pull the switch plunger rod out of the switch toward the brake pedal arm, as far as you can without using excessive force. Next, return the brake pedal to the pedal stop position against the pedal stop and pull the brake pedal toward the rear to push the brake light switch actuating plunger rod into the switch housing limited by the travel of the brake pedal arm rear travel stop position. This procedure automatically adjusts the brake light switch correctly.
If the brake lights still don't turn off with the brake pedal released, check the brake pedal arm for sticking or binding that is preventing the brake pedal arm from returning fully to the pedal stop when the brake is released.

Feb 21, 2011 | 2002 Audi A4

1 Answer

The emergency brake light stays on and I have no brake lights. The e brake is not engaged. The fuses are good I replaced the brake light switch and checked the connections under the truck at the rear of...

mcdevito75 here, After you installed new brake light swith did you adjust to make sure it"s contacting the brake mechanism, also check for power at the switches plug. Check also your brake light bulbs.

Jun 05, 2010 | 1991 Chevrolet C1500

1 Answer

Brake lights (all 3) stays on in my 2001 Mercedes CLK 320. What could be the problem?

check the brake light switch,which is located on the brake pedal itself

Mar 08, 2010 | 2001 Mercedes-Benz CLK-Class

Not finding what you are looking for?
Cars & Trucks Logo

Related Topics:

2,412 people viewed this question

Ask a Question

Usually answered in minutes!

Top Mercedes-Benz Experts

Colin Stickland
Colin Stickland

Level 3 Expert

22484 Answers


Level 3 Expert

84540 Answers

Jonah Oneal

Level 3 Expert

14092 Answers

Are you a Mercedes-Benz Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides