ABS problem?

[theloosa6]

I have been "fighting" a 01542 - Yaw Rate Sensor (G202): Implausible Signal code problem but I'm starting to think it might be my ABS? Symptoms: - ESP comes on randomly even while driving on flat straight roads. Sometimes it doesn't come on for a whole week. Recently, comes on more frequently. - Ocassionally and happening more often, short burst of a slight to fairly loud "scraping/grinding" noise when braking (at slow speed like when coming to a stop). Brake pedal at that moment feels like it gives way. Since taking ownershop of the car, we have always heard a slight scraping/grinding noise when backing up or starting out after starting the car. They informed me that this was the ABS "calibrating" it self? In any case, same type of noise but MUCH louder. - ABS light came on ONCE last week (for the first time) but have not seen it since nor are there any codes other than the brake switch and the yaw sensor codes. - I have noticed that my rear wheels seem to get dirtier that the fronts, isn't it usually the other way around? My fronts brakes are not applying pressure? I recently replaced the brake switch to clear the brake switch error codes which I read in a few threads that was the solution to some ESP problems. Any one with thoughts on how I can verify if I do have a degrading ABS module and it the ugly sounds I'm occasionally experiencing is related to the ABS? TIA.

[4Driver4]

How long has this been happening? Was any repair work done prior to the repair? How long have you had the car.

[GTA_Driver]

The dirty back wheels could be because the break pad compound on the rear pads is different than the front.

[theloosa6]

Originally Posted by 4Driver4

How long has this been happening? Was any repair work done prior to the repair? How long have you had the car.

I would guess that the ESP light--->yaw sensor error code started around late October last year. Noise only happened once or twice and lately more often in the last month. Brake switch codes was recent. We bought the car as CPO from dealer in 2006

[theloosa6]

Originally Posted by GTA_Driver

The dirty back wheels could be because the break pad compound on the rear pads is different than the front.

yes, thought about that but I assumed that they are the same...I did check yesterday after driving and the rotors were warm so they probably are engaging as they should...

[theloosa6]

Originally Posted by theloosa6

I would guess that the ESP light--->yaw sensor error code started around late October last year. Noise only happened once or twice and lately more often in the last month. Brake switch codes was recent. We bought the car as CPO from dealer in 2006

sorry...it's a 2003 and we bought it in 2004 from the dealer...thanks

[theloosa6]

Does the yaw sensor need to be "calibrated" after installation?

[SloopJohnB@mac.com]

Let's try this placement in the thread: There are weird cases of broken tone rings on the outer CV joint but the joint has to be removed from the outer wheel bearing/carrier to inspect it. That's if you can isolate the problem to one or two wheels otherwise you have to inspect them all, not particularly fun or inexpensive if you have to pay for it.

A new yaw sensor is not cheap either but as with most electronic modules when you get such an error the only way to check it out is to replace the module with a known good one and see if the code goes stays gone (after you cancel the code, of course).

If you don't have a vag-com or the inclination to purchase one and buy a yaw sensor (considerably discounted on-line I'd bet compared to a dealer) and do the exchange yourself your best bet is probably to go to a good independent and have them do it...make sure you get a warranty on the yaw sensor/repair such that if the yaw sensor isn't the problem they'll put your old one back and find the real problem.

[theloosa6]

Originally Posted by SloopJohnB@mac.com

Let's try this placement in the thread: There are weird cases of broken tone rings on the outer CV joint but the joint has to be removed from the outer wheel bearing/carrier to inspect it. That's if you can isolate the problem to one or two wheels otherwise you have to inspect them all, not particularly fun or inexpensive if you have to pay for it.

A new yaw sensor is not cheap either but as with most electronic modules when you get such an error the only way to check it out is to replace the module with a known good one and see if the code goes stays gone (after you cancel the code, of course).

If you don't have a vag-com or the inclination to purchase one and buy a yaw sensor (considerably discounted on-line I'd bet compared to a dealer) and do the exchange yourself your best bet is probably to go to a good independent and have them do it...make sure you get a warranty on the yaw sensor/repair such that if the yaw sensor isn't the problem they'll put your old one back and find the real problem.

Thanks for the input...

"tone rings"...oh boy, not sure I want to know what those are at this point!

Yes, yaw sensors are ridculous ($650) and not much different in cost whether online or from the stealer...I did replace with a used (but supposedly tested) one and the ESP light problem did go away for a while but then it came back. I do see that other related problems can cause this error code to show up so I'm hoping it is something else! Replacement is lifting the back seat and 2 nuts so that's easy enough to do...maybe I can find someone with the same model and ask if I can borrow their sensor..

Thanks again.

[SloopJohnB@mac.com]

Originally Posted by theloosa6

Thanks for the input...

"tone rings"...oh boy, not sure I want to know what those are at this point!

Yes, yaw sensors are ridculous ($650) and not much different in cost whether online or from the stealer...I did replace with a used (but supposedly tested) one and the ESP light problem did go away for a while but then it came back. I do see that other related problems can cause this error code to show up so I'm hoping it is something else! Replacement is lifting the back seat and 2 nuts so that's easy enough to do...maybe I can find someone with the same model and ask if I can borrow their sensor..

Thanks again.

This is a tone ring on a CV joint.
http://forums.audiworld.com/showthread.php?t=2054269

Generally if the tone rings aren't physically cracked or worn (they should have NO wear on them..if they do something like the sensor got pushed in or a rock damaged it) they're ok. I don't think the rings can be replaced w/o replacing the out CV joint but look around...I recall reading about some guy who made a bunch of them from billet or found Taurus rings that could be pressed on.
Clearly anyone who rebuilds CV joints has access to tone rings.