zcct04

I replaced pads and sensors on the C63 last weekend. Driving to work the next morning I got the alert again about needing new pads. Grrr Couldn't tell which sensor wasn't plugged in well enough to make a good connection so had to guess. And of course I guessed wrong, which meant I ended up jacking it up twice and pulling each of wheels.

Word to the wise when replacing sensors - before you remount the wheels, turn on the ignition and let it sit for 30 seconds to be sure the sensor plug is fully seated and making a good connection to the wiring harness.

Vladds

My C63 was fine with the sensor replacement.

My wife's former E36 BMW was a different sensor story. I tried everything including completely removing the sensor wiring and completely shunting the contact and reset procedures that I found online. Nothing seemed to work. In the end, I did a cluster replacement, because I was preparing to sell the car and it had the stupid mileage counter LCD broken and I ended up finding a cluster with similar mileage and swapping it.
Then ...... miraculously... the sensor light went away. I HATED the E36. never again. My Alfa Romeo 164 was more reliable than that, but in fairness did not last to 230 K miles like the E36. But to get to that number with the E36 was blood, sweat and tears.

And because I believe what I say, we replaced for her the E36 with an.... Italian car, a Fiat Abarth.
And... surprise, surprise... the Abarth is a reliable car to 45 K miles. Of course this is just a subjective statement, as the Abart did not yet reach 160 K miles, as the E36 had when we started with it and there is no telling what it will do at 136-225 K miles, reliability-wise and even if it does, this is newer technology, than the 1998 BMW E36. However, newer thechnology BMW are crap, reliability-wise and even at Abarth mileage like 40K miles, you see all kinds of reliability complaints posted.
Sorry, I have to stop here. Also, full disclosure, I worked in the 90's for Fiat Auto.

m3driver

Correct. Spent 5 minutes arguing with the local MB dealer parts guy - who told there was no bolt anywhere on the caliper until we opened up the exploded view and I pointed to it. Bolt and sensor was $22. The somewhat odd thing was that when I just bolted the bracket to the caliper the sensor warning went away. So initially the bracket was rubbing on the wheel? Was it grounded that way? When I zipped tied it out of the way so it wouldn't rub is when I got the warning light so I'm guessing it was grounding against the wheel? Maybe. Anyway light is out and all is well after non-existent bolt replaced.

m3driver

Seemed like all I did this weekend was work out sensor problems. On the E90 325i I got a new BMW sensor and replaced the non-BMW one and slam bang thank you mam brake warning light went out. Old sensor evidently had a short internally.

Then immediately after I fixed that the garage door refused to close. F^&King broken wire in the door safety sensor power supply. Jeez.

mjz3348

This has been a great thread ... a few days ago my check brake pad sensor popped up on the instrument panel. I have no idea which wheel triggered this, but when I checked my brakes they had plenty of pad left on all four - in fact they still look pretty thick even though the car has 25k miles. What do I look for that may be broken or loose in order to get rid of the warning. I like the idea of a brake sensor so I don't have to check it, but as some wrote on this thread, the sensors aren't accurate.

Thanks

m3driver

There is one front left and one rear right. if the bracket is loose as mine was you'll get a sensor indication. The sensors are fairly afforable at $10 and there isn't an hoop jumping to reset the warning compared to the BMW system.

Mort

^^ Typo? Brake sensors are right front and right rear. You probably have to replace the sensor(s) if you are getting a false warning.

zcct04

I can't guarantee this about other model years and countries, but I'm with Mort - my '12 coupe in USA is right side, front and rear.

Before I replaced them, I'd try to unplug them from your wiring harness and then really firmly push them back in. I'd also check the bolt that attaches the harness clip to the car (see notes above from m3driver) and make sure it's tight - it evidently needs a good ground.

m3driver

ha yep. BMW do the diagonal front to rear sensor thing. Been working on too many cars lately ;-)

Still just prefer the metal clip thing that grinds against the rotor and squeals when the pads are low ;-)

Vpatriota

Quick question: are the C 63 BlackSeries brake sensors the same? I know brakes are different, but sensors? (Ref: A 171 540 06 17). Stealership is charging me something around 250 usd, so I’m probably buying from somewhere else.

m3driver

is that in american dollars? My price thru the MB parts vendor I use for my business is $9.50 after I mark it up 100%.....

That p/n is used in some applications as far back as 2003 on an SL500

BTW - that p/n is not for use with ceramic brakes

Vpatriota

Yes, American Dollars, can you believe it? When I looked for it online some retailers charged less than 20dollars the pair. Outrageous. Talk about overcharging, right?
I’m also pretty sure my car does not have the carbon/ceramic brakes.

onkm

i found out part number 211-540-17-17 it also fit in c63 amg
but it called sender unit.
anyone knows the different?