Brake pad wear warning light - PeachParts Mercedes-Benz Forum

mach0415 · #1 09-17-2010, 04:55 AM

So, my brake pad wear warning light proves out after cranking up. But, my rear brakes are worn out and time for a change. The warning light is not on and all sensors are intact EXCEPT the left front warning cable broke. Are these things somehow wired in series? or do they all feed in parallel to the ground circuit? I suppose I could look up the diagram on my Alldata, but I woke up at 3am worrying about the stupid thing. Although, I have fixed many cars in my sleep

tangofox007 · #2 09-17-2010, 08:11 AM

Quote:

Originally Posted by mach0415

Are these things somehow wired in series?

If they were, all your pads would have to wear thin before the light came on. (That is not the case.)

Quote:

Originally Posted by mach0415

But, my rear brakes are worn out and time for a change. The warning light is not on...

You have wear sensors on the rear?

Quote:

Originally Posted by mach0415

So, my brake pad wear warning light proves out after cranking up.

Now I will be awake at 3am contemplating the meaning of "proves out."

#3 09-17-2010, 08:28 AM

They are in parallel, and only in the front on your car. Either front brake should give you a light. You have the check the rears yourself.

mach0415 · #4 09-18-2010, 06:03 AM

Ok, my mistake front only, then. I will have to replace that left front wire that is broken.

"Proves out" means that it comes on to show the system is functioning and then goes off to tell you it is functioning correctly with no "hard faults."
This is similar to ABS, MIL, TPMS, TC, SRS, etc. lights

. Some call it a bulb check, but it telling you more than just that the bulb is working.

tangofox007 · #5 09-18-2010, 10:35 AM

Quote:

Originally Posted by mach0415

"Proves out" means that it comes on to show the system is functioning and then goes off to tell you it is functioning correctly with no "hard faults."
This is similar to ABS, MIL, TPMS, TC, SRS, etc. lights

. Some call it a bulb check, but it telling you more than just that the bulb is working.

The pad wear indicator "system" is totally lacking the level of sophistication that you envision. The fact that it "proves out" with one broken sensor wire should "prove" that.