W211 "Malfunction"

Mercedes 190E

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Hi All

Last night when I started the E320, I got the warning "Brake service-visit workshop". It then reminded me again when I turned off. When I used the car again later in the evening, nothing came up, so I scrolled through the menu to be told "No malfunction". Is this normal behaviour? I thought that malfunctions stayed in the memory until reset?
Last question-what does "Brake service" usually mean-pads?
Thanks! :D
 

television

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this is odd,but I would not worry too much, the only thing that comes to my mind is a poor contact where the sensor plugs into the brake pad
 

jberks

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When pads get low, the sensor will still be some way into the pad material and so occasionally touch the disc when conditions are right but not every time. As more material wears away revealing more of the sensor, making contact more often until it alerts every time.
Most warnings of this type - pads, low washer fluid etc only stay listed until you turn off the ignition. They then go away until triggered again.
So, chances are your pads are on their last legs and you need to make plans to have them replaced within the next 1000 miles or so. It gives you time to ring round and get a good price :)
 

television

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When pads get low, the sensor will still be some way into the pad material and so occasionally touch the disc when conditions are right but not every time. As more material wears away revealing more of the sensor, making contact more often until it alerts every time.
Most warnings of this type - pads, low washer fluid etc only stay listed until you turn off the ignition. They then go away until triggered again.
So, chances are your pads are on their last legs and you need to make plans to have them replaced within the next 1000 miles or so. It gives you time to ring round and get a good price :)



Not on this car,it uses a 2 wire principle where the wire is cut when the pads are worn down, once cut the light is permanently on until the new pad and sensor have been fitted.
 
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Mercedes 190E

Mercedes 190E

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Hmm..so on balance, likely to be a connection somewhere then? I will have a look at the pads anyway just to be sure and then see if it reoccurs....
Thanks guys!
 

television

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Hmm..so on balance, likely to be a connection somewhere then? I will have a look at the pads anyway just to be sure and then see if it reoccurs....
Thanks guys!

I was wrong to say where the sensor is pushed into the pad.

You could pull the connector out of the pad, and the lamp will not come on. any problem should be at the other end of the sensor where it plugs into the socket .

The older system, a one wire sensor used an insulated pin in the pad, when the pads wore to their limits, the brake disc wore through the insulation on the pin until it made contact with the disc. This would turn the lamp on for the remainder of that journey. On a re start the lamp would only come on again once the brake pedal had been pushed.

The 2 wire is not the same, and work in a closed circuit loop. On these cars with 2 wires, once the pads are down to their limit, the disc cuts the wire and the system is then open circuit, the lamp comes on, and it will remain on until a new pad and sensor has been fitted.
 

seabadger

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'Brake service - visit workshop' warning

Hi All

Last night when I started the E320, I got the warning "Brake service-visit workshop". It then reminded me again when I turned off. When I used the car again later in the evening, nothing came up, so I scrolled through the menu to be told "No malfunction". Is this normal behaviour? I thought that malfunctions stayed in the memory until reset?
Last question-what does "Brake service" usually mean-pads?
Thanks! :D

I had this problem on my W211 - it came and went over a period of 2-3 months until Ellsy Tanners suggested I changed the brake light switch.
It cost about £6.00. I fitted it myself and that cured the problem.

Regards
Seabadger
 
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