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Marty, Mercedes Technician
Category: Mercedes
Satisfied Customers: 53979
Experience:  Bosch Certified Master Tech. Over 35 years experience.
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My husband recently replaced the rotors and pads on our

Customer Question

My husband recently replaced the rotors and pads on our S550. Days later the parking brake light came on after having new rear tires put on. I parked and did who knows what and it went off. Weeks later I had some from the end work done and when the mechanic called for me to pick it up he informed me the parking brake light was on a d he couldn't get it to go off. To this day I cannot figure out how to fix it. I tried the manual release through the gas cap location (not sure what that's called ;)....didn't work, but it's not engaged so I didn't think it would make a difference.) I've checked the's fine. Read something about looking under the dash for a small press buttons, don't know how to get under the dash! Do you think it is a broken sensor from changing the rotors? If so how hard is that to repair and how costly. We just want to sell the darn thing but now it seems it one thing after another!
Submitted: 1 year ago.
Category: Mercedes
Expert:  Marty replied 1 year ago.

Hi, my name is***** the warning light actually display the word PARK or PARKING BRAKE?

Customer: replied 1 year ago.
There are two lights both say park one in red one in yellow
Customer: replied 1 year ago.
Then was the car is started the yellow goes away but the red remains
Customer: replied 1 year ago.
On the dash it say Park Parking Brake See Operating Manual
Customer: replied 1 year ago.
Hi marty...BTW :)
Customer: replied 1 year ago.
Do i need to adjust that thingy under the rear seat? Lol
Expert:  Marty replied 1 year ago.

Okay, the fault will be with the electronic parking brake controller. Let me check to see if there is anything he may have done in the rear that could cause this. I'll reply back shortly.

Customer: replied 1 year ago.
OK thanks
Expert:  Marty replied 1 year ago.

Looking at the rear calipers and parking brake I think the only thing that may have happened is he disconnected or damaged one of the parking brake cables. He should inspect the cables and make sure that they are attached and correctly fitted into their brackets. If the cables have come loose the brake will not function properly and the warning light will come on. If the cables are fitted properly you will need to get the car connected to the Mercedes tester to check for fault codes and reset the parking brake system.

Customer: replied 1 year ago.
OK so I will have him check out those cables before bothering with the electronic braking control. Are both very difficult to repair? Expensive?
Expert:  Marty replied 1 year ago.

The cables are not too bad but the controller is pricey. If the cables are not the problem they may be able to perform a reset on the parking brake control unit.

Customer: replied 1 year ago.
Pricey like 100's or 1000's lol more than $300? Is it something we can do or does the dealer have to do it
Expert:  Marty replied 1 year ago.

The cables are $60 and $85 but the controller is $950. Replacing the cable is probably not something that you should attempt.

Expert:  Marty replied 1 year ago.

Sorry I hit send prematurely. Replacing the cable is probably not something that you should attempt. The Mercedes Star Diagnosis tester is required for moving the brake controller into the assembly position.

Expert:  Marty replied 1 year ago.

Let me know if you need anything else. Please don't forget to rate my service in order for the website to credit me for helping you.