Break Wear Warning

[stormin]

Hi I have a 2002 "S"Class 320 CDI and a short while ago the Brake wear warning canm up on the dashboard display, So I replaced the Front pads and sensor leads from German and Swedish car parts, but i continue to get the warning message so i called my local Mercedes Dealer who told me they sometimes have this problem with non original parts ie: if the pad has a high metal content it may be picked up by the sensor, he also said thet some of the non original sensors can play up, so i have today fitted two new Mercedes sensors but before inserting them into the pads I just pluged them into the car and started it up as to eliminate the non original pad possibility but i still get the warning message Mercedes also tell me the brake sensors are independent to the cars computer and does not need re-setting, as you can guess I am now a bit lost for ideas so any help would be fantastic, the only other thing is when i re-start the car it shows no malfunctions for a second then the message pops up.:???:

Thanks
Norm.

 

[television]

Norman, some cars like the larger ones have sensors on the rear, have you looked at them,often not fitted but are sometimes. have a look.

Malcolm

 

[television]

Just adding something,if there are no rear sensors, wash the connector sockets off with a little petrol. It is a fact that copper grease can give false readings this is why it has been superseeded .

malcolm

 

[stormin]

Thanks for your reply the sockets are clean and there are no sensors on the rear wheels as i thought that may have been the case so i had a look the other week it's just frustrating to get this message when I know the brakes are ok !!!

Norm.

 

[television]

I think then that your dealer may be umpty as you fitted your own pads, I have seen this before.

If you care to put up your VIN first 6 numbers I will see what I can find to see if this can be removed on the Star diagnosis

WDB220---

malcolm

 

[stormin]

Hi Malcolm
The VIN is :WDB2200262A is this enough or do you need the rest?
Thanks
Norm.

 

[television]

Hi Malcolm
The VIN is :WDB2200262A is this enough or do you need the rest?
Thanks
Norm.

I will look tonight.

Malcolm

 

[stormin]

Hi Malcolm did you ever get a chance to see if my warning needs to be turned off with the star computer?

Regards
Norm.

 

[television]

Hi Malcolm did you ever get a chance to see if my warning needs to be turned off with the star computer?

Regards
Norm.

I am ashamed that I forgot, sometimes I lose threads.
I will post back later in the night either way.

Very sorry Malcolm

 

[television]

As said earlier I have never heard of this fault, and I have been through 290 pages and nothing

I think all you can do is get the car onto a STAR tester to erase the fault code.

I would love to know what the code reader says.

Malcolm

 

[Ultymate]

You'll probably find one of the warning wires has shorted to earth somewhere on route to the front calipers and hence put up the warning light check for continuity to earth on the wiring both sides

 

[stormin]

Thanks malcolm

I will let you know if i find out anything as for Ultymate's reply I must admit I have started to think along those lines as everything was ok until I changed the pads, So how do I check for continuity I have a meter but do I check between both pins on the same socket or one pin at a time to earth, sorry to ask what is probably a stupid question but vehicle electrics are not my strong point.

Regards
Norm.

 

[eric242340]

Thanks malcolm

I will let you know if i find out anything as for Ultymate's reply I must admit I have started to think along those lines as everything was ok until I changed the pads, So how do I check for continuity I have a meter but do I check between both pins on the same socket or one pin at a time to earth, sorry to ask what is probably a stupid question but vehicle electrics are not my strong point.

Regards
Norm.

Hi Norm, Star D will not reset nor check this problem. You have a short to ground (earth). Check for continuety between the sensor wires and earth. Also a common fault with these sensors is not pushing the connector into the socket far enough. Check this.

 

[television]

Thanks malcolm

I will let you know if i find out anything as for Ultymate's reply I must admit I have started to think along those lines as everything was ok until I changed the pads, So how do I check for continuity I have a meter but do I check between both pins on the same socket or one pin at a time to earth, sorry to ask what is probably a stupid question but vehicle electrics are not my strong point.

Regards
Norm.

Unplug both sensors, and with an Ω meter check and see what the resistance is down to the earth/chassis/body from the sensor lead sockets.

The post by eric242340 saying that the leads not pushed in far enough is not correct and the opposite to that is more true, since only a perfect contact to ground can light the lamp.

If this circuit is just simple where the pad when worn down completes the circuit, then there should be 12volt present on the sensor wires/plugs when the lamp is not lit.

If I can see my sensors through the wheel on my car I will check this in the morning it will not help you,but it will help me.

Do unplug the leads from the sockets on the stub axle to test, as there was no problem until you changed the pads then by rights the fault can only be on the sockets where the leads plug in. With the leads completely unplugged turn on the ign and have someone watch the lamp while you wriggle the socket and cable going to it both sides and see it the lamp flickers or goes out.

Malcolm

 

[eric242340]

The post by eric242340 saying that the leads not pushed in far enough is not correct and the opposite to that is more true, since only a perfect contact to ground can light the lamp.

I Stand corrected on this one. Malcolm is correct, if the sensor is not connected properly then there could be no ground. Having read this thread again I see its only the brake pad wear warning light. I have ABS on the brain at the moment and this confused me. sorry.

 

[eGuru]

Had all four discs and pads replaced today. This thread came to mind and asked about the sensors. From what I have been told there shoud be 2 sensors and only one on the rear. Replaced all 3 sensors for me. Hope this helps.
Jay

 

[television]

Its a funny world, some car have the provision for 2 front and only use one (mine) and have the fittings on the rear and they are not used, though I could plug them in if I wished.

Malcolm

 

[stormin]

Thank you all for your help and advice over my Brake warning message I did look at the rear wheel a while ago but only the nearside as i guessed I have a sensor on both sides at the front so when i could not see one on the nearside my brain the size of a pea did not tell me to look at the offside, and the other day i was washing off the wheels and i saw a sensor on the offside have now replaced the pads and sensor and guess what the message has gone off DOH!!!!
So thank you all once again for your help

I also have some anti-roll bar drop links for sale as i am selling the car all the info in on the for sale part of this forum

Regards
Norm
Kent Limos Ltd

 

[television]

The main thing is that it is OK now