Gentlemen, could someone please provide some help :

I have a 1999 ML430 with only 20K miles.

I has on three occasions had the front brakes on both sides start dragging and experienced a loss of power.

After letting it set over night the brakes no longer drag.

It has at times had the BAS/EPS light comes on.

After letting it set over night the light goes out.

The most recent time I took it to the local MB Dealership and they tell me I need a YAW Rate Sensor MB#163-542-16-18.

I found the part at a discount MB dealer for $187.50 and placed the order. Within a day of placing the order MB comes out with a new part#163-542-23-18 and the price goes to $363.00.

In my searching of the various ML forum no one has reported a YAW Rate Sensor problem. I therefore think something else wrong.

I have replace the brake light switch and also had the brake fluid purged and replaced by the local MB dealer.

Does anyone have a suggestion of what may be the problem ?

Can someone post a MB WIS for replacement of the YAW Rate Sensor and or tell me where it is located on the ML.

Thanks, Charlie

That Yaw rate sensor is a VERY low fail part..sold only 1 this year..they do fail


Located on the "tunnel" behind the gear-shifter beneath the window switch assembly.

__________________
MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)
Retired Moderator

Sooooo, what exactly is the purpose of the Yaw Rate Sensor when functioning properly? And why would it apply brakes when malfunctioning?
Just want to know.

__________________
Thank You!
Fred
2009 ML350
2004 SL600
2004 SL500
1996 SL600
2002 SLK32
2005 CLK320 cabrio
2003 ML350
1997 C280 Sport

Yaw(rate) was a boating term for years. For MB's that term emerged in 1996 here is the USA.. means that the car speed isn't equal to the steering wheel angle VS the wheel speed of each wheel.

__________________
MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)
Retired Moderator

M.B. Doc

Thanks for your comments.

Is the YAW Rate sensor replacement a straight plug and play DIY.

In other words disconnect battery, locate sensor, un-plug old and plug in new, and reconnect battery.

Or does it require some re-programming by the MB computer ?



Thanks again Charlie

Just plug & play...no battery dis-connect needed.

__________________
MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)
Retired Moderator

M.B. Doc

I tried to locate the Yaw Rate Sensor, MB part #163-542-16-18 as per the above post but did not find it.

When removing the center cousole and all the related plastic parts the closest electrical module I found was a #163-542-06-18. In checking an online parts supplier it was listed as a Yaw Rate Sensor for a C230 2002-2005 and a Stability Control Accelerometer for an ML320, ML430 1998-2002.

What gives are we talking about the same part ? Is this what needs to be replaced ?

Thanks for your help
Charlie

I would guess a yaw rate sensor would in fact be an accelerometer.

__________________
Thank You!
Fred
2009 ML350
2004 SL600
2004 SL500
1996 SL600
2002 SLK32
2005 CLK320 cabrio
2003 ML350
1997 C280 Sport

The ML has both, a yaw rate sensor, which senses a turning motion around the vertical axis, and a lateral acceleration sensor. As MB DOC says, the yaw rate sensor doesn't fail often. I wonder how the dealer diagnosed it? Which diagnostic error codes were set? Usually when the ESP/BAS malfunction indicator light comes on, it's a failed brake pedal switch, which is around $15.

__________________
W163.154, M112.942, 722.662, ZF.970.402

I have already replaced the brake light switch and that did not solve the problem.

My problem is occasionally having both front brakes being applied with out my touching the brake pedal.

Although the above post do note the YAW rate sensor seldom fails, no one has confirmed if it does fail it can cause both front brakes to be applied.

Has anyone actually had a similiar problem and found the solution ?

Should I replace the part in my ML # 163-542-06-18, available for $97.00, with the newest part # 163-542-23-18 at $484.00 ?

Thanks, Charlie

My name is Enrique, I have a 2001 ML320 with 53K miles and recently had the same problem. (Long story short) brakes came on all of a sudden and engine would not go above 1000 RPM and would apply the breaks and ABS everytime I would try to speed up above 1000 RPM's.

3 different scenarios: Rainy going down the hill slow with debris on the road, Sunny and hot going 25 MPH straight without breaking, and one time going 45 MPH into a curve on the freeway. Luckily I am still alive to tell this and I did not get involved in an accident. Took the car to a local shop and they replaced the brake light switch (code: C1200) and drove it for 100 miles and it hasn't done it anymore. I wasn't feeling confident driving the car anymore so I got all the codes from the local shop and took the car to the dealership. All the codes cleared by that shop were these:

ESP C1200
ESP C1120 (showed up 3 times)
BAS C1025
AAM B1858
AAM B1040
AAM B1783 (showed up twice)

The experience mechanics at the dealer told me that they didn't "see" the Yaw Rate Sensor causing the problem and they pretty much said : "drive it and see if it happens again" The problem is, if it happens I could die... and I don't want to just sell the car because that is totally unethical. Please help!!!

One more thing, the Yaw Rate Sensor was quoted at $530 US dollars and it is not a switch and go thing, The mechanics say you have to plug the car to the computer and drive it a certain way to set the sensor.

Enrique, have you had the break apply all of a sudden after you replaced the YAW sensor? I have the same problem and had my Lateral Accelerometer replaced which did not fix it.

Hello guys!
May I ask for some help here? I have an ML320 2000 qith the same problem you reportes. The point is that I live in Brazil and this part here, for sell in a MB authorize dealer costs just US$ 4.000 (!!!). I've trying to find this part at some US store on the internet but I didn't find till now. Can anybody suggest me a dealer where I can buy it? Thanks!!!

aloha doc!
here in da islands with an ML500 2002 64,000 miles...
ESP light has come on after about 3-4minutes of driving.....so i started car and turned the wheel all the way to right then left and drove away.....
brakes locked up several times.....i turned off the car, waited a few minutes and drove again...ESP light came back on and brakes did not lock up...have driven it all day today, no problem and ESP light came on every time....
no MBZ dealer on our island, just independent rip-off garages....
would love to trouble shoot and replace a part or two b4 giving in to the sharks...
any suggestions?
Mahalo!