Question about 2007 Mercedes-Benz ML320 CDI

2 Answers

Brake lights stay on

I have a Mercedes 2002 M320 class. The brake lights are staying on when I drive........Any tips how to shut them off?

also the cruise control has stopped working and the drivers side automatic door lock stopped working...could all of this be related??


Posted by newm5 on

  • newm5 Aug 06, 2008

    Thank you so much! We got and replaced the switch right away and it fixed the brake-light problem, which was our main concern. Not sure if it fixxed the cruise control yet as we have not been on a highway to use it...but it made sense that the brake light staying on probably affected the cruise too.

    The door problem still remains though. The drivers side lock will not lock or unlock with the key-remote nor the auto. locks inside. Any suggestions??

    Also--we unhooked the battery initially to try to fix the brake problem and now the car radio is saying "Enter Security Code" and will not play. We have no clue what the Security Code is and don't have the manuel. Any ideas on this.

    Thanks again for the help with the brake problem!



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Your brake light switch is stuck on, this is also why the cruise is in-op, the cruise is turned off anytime you touch the brake pedal otherwise the car would try to accelerate when you tried braking. The brake light switch is located above the brake pedal, look up the arm the pedal is attached to and you will see it, the switch is not real expensive, and it is easy to install with simple hand tools. As far as the door lock issue fix the brake light switch and try it, not sure it is related unless it all started at the time the brake lights started staying on. Post back after you replace the switch if door problem remains. Thanks

Posted on Aug 06, 2008

  • 3 more comments 
  • Marvin
    Marvin Aug 06, 2008

    There is a little linkage rod from the key cylinder to the lock itself, these on occasion break or work loose, the resault the key will no unlock the door or the remote.

  • redbirds6467 Sep 16, 2010

    Thank you so much! Replaced the switch and now the brake lights are operating normally, and the cruise control works again. Also, we had a problem with our key locking the car, we just replaced the batteries and did a re-sync as explained in the car users manual. Worked like a charm!

  • rancherprice
    rancherprice Nov 30, 2012

    How do you re-sync the key?

  • rancherprice
    rancherprice Nov 30, 2012

    How did you re-sync your key?

  • Marvin
    Marvin Dec 01, 2012

    What does this have to do with brake lights??




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You can get the radio code at the dealer for free,if its not the correct code coming up on the vmi,get the last 8 digits off of the serial number on the head unit,can be pulled out with a set of radio keys,and have them run a radio code search,as for the door problem,if thats the only door that wont lock unlock,i would say the locking actuator in the drivers door has gone bad and needs to be replaced

Posted on Aug 10, 2008


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