Just joined the forum. Trying to keep my wife's 2001 C320 from electrically disintegrating. Bought the chinese carsoft to deal with the CAN bus crap and have had success with it. The lateral acceleration sensor was coding and the real-time display showed 7.8 while parked (should be zero). That's what led me to this thread. Thanks for showing me where it is located ! After extracting the unit I hooked it up to 5V power supply and noticed that the third wire was analog output that seemed to be working (output voltage would move up and down as I shook the thing side to side). So I put it back in the car. Maybe after 8 years it was just a connection problem or it could be intermittant. We'll see. The point is that since it is an analog ouput sensor, if it fails again I have the option of just hooking up two resistors to the connector instead of buying a new one. Of course the ESP would then always think the car had zero lateral acceleration but I'm not the type to think that a working ESP is a neccessity in life. Here is a sketch of the geometry of the three connector terminals when looking at the end of the wiring harness after unplugging the sensor: (the GND is the "middle" pin that is offset from the other two, the little "o" are the connector terminal)

-------------------GND
--------------------o
Analog output --- o , , o ---- +5V supply

What I would do is connect, say, a 2Kohm resistor from GND to the analog output and a second 2Kohm resistor from +5V to the analog output. This would put 2.5V on the analog output which corresponds to zero lateral acceleration. Then double check by using the real-time display of the tester to verify that the reading is close enough to zero to keep the ESP system happy.

 

Excellent info. Horrible idea.

 

+1

 

OK, it was a horrible idea. The computer was happy in the garage and driving straight but turning right from a stop made the system do funny things.

So I did some research into yaw sensors and will try a real solution but using new sensor technology. Will post when and if I get it working. Since the new law requires all cars to be equipped with ESP in a couple years, a lot of new (and cheap) sensors have recently been announced by major chip makers. Some as little as $4. Should just be a matter of matching the output of a new one to the old one. Meaning how many millivolts of output per degree of yaw. What the sensors do is output 2.5V at standstill, then as you rotate (yaw) one way or the other, the voltage goes either up or down from there.

 

Sounds like a much better idea. Just be careful... if I were you I would find a nice empty parking lot and go wild with it to make sure ESP responds properly in all situations with the new sensor. False readings from the sensor could potentially cause a crash if the system responds wrong and makes a skid worse.

 

+1 i personally would rather just spend the money on the oem part because my life and everyone's life around me means more to me than saving a few buck on a part. lol that is funny i just read what i wrote i am not really totally awake. i guess i care about people so that must me why i want to be a cop. oh that must be a lie i just want to have a cop car and gun and pull over every prius drive i can.

 

Just a thought - have you done a steering angle sensor reset? The angle sensor & yaw sensor work in unison.

Turn steering from lock to lock 5 times.

 

I made a prototype and tested it today and so far no codes. My little box mounts on the two screws where the yaw sensor is, but can replace both the yaw and acceleration sensors, or just the yaw sensor. It's calibrated electrically to match the original sensor characteristics.

1) The original yaw sensor is still working but very sensitive to vibration. I believe this is what was causing the codes and the random strange jerks in the vehicle motion when driving. It's probably on it's way out. I put it on a rotating platform and measured the output in units of millivolts per degree per second (mV/deg/s). Also contacted the maker of the sensor and got the full scale range from them (deg/sec). Then set the gain on my replacement to match.

2) The acceleration sensor is easier to calibrate because all you have to do is operate the unit (out of the car) and then turn it so the connector is straight up, then straight down, and measure the output voltage. Again, I set the gain on my unit to match the original.

I have no intention of trying to skid the car to test the ESP. As an engineer, rather than say, a lawyer, I know that there is nothing "magic" about the original sensors. We live in a warm climate and have never engaged the ESP in 8 years of driving, and we don't plan on starting now. I'm not advocating my approach to everyone. I wanted to show that it is possible to overcome the manufacturer charging whatever they want for replacement items. Our car also has the power seat modules that drained the battery and I have rewired those per the instructions on the forum instead of buying new ones. The sad thing is that the shop could just re-flash the memory in all these failing control units but they would of course rather sell a new one. A friend of mine had a few problems with his instrument panel and when he visited a different shop for something else he mentioned it and they fixed it no charge instead of a $3K dashboard estimate from the other shop. They wouldn't tell him what they did but I know that they just re-flashed it. Sorry, I'm wandering a bit here.

 

Hi Guys.
I had a similar problem.

The ESP light was showing on the dash, and the Hazard light switch was constantly flashing.

Also not so long ago, on a wet road, which had a long curve, the car badly lost control.

Anyways, today i decided to have a play, so took both the sensors out, took pics, started the car up. Then put them back.

The Warning lights have gone, although i havent driven the car at all yet.

How would i know the ESP is working?
Also how do i reset the steering sensor?

 

Reset the steering angle sensor by turning steering from lock to lock 5 times. If you have no ESP light or message saying "ESP not available" it should be working. Otherwise take the car onto a skid pan.

 

Thats great thanks.
When i drove the car earlier, i started it and did the lock to lock thing 6 times. Lol so i hope its done.

No ESP lights or flashing indicator.. so so far thumbs up.

Now i just have to sort out steering wheel shake at high speed breaking.

 

Car is an 01 c32amg (02)
Have posted on the amg 32/55 to no avail - A little help please?
I have had the esp light come on each ignition for a while, had some power loss the other day so CM30 (IC pump) was replaced however loss came again (then gone)- Autologic pulled - B24/15rotery speed and lateral acceleration sensor"
the yaw sensor in the trunk A0025428918Q04 costs the earth and isn't to do with the speed, the lateral speed sensor 1635420618 I think is the correct p/n for c32 but where is it located? I cant find out where it is? Anyone know? Cheers,
_____________

 

Hello! I own a mercedez w203 and while driving with 30miles, it stopped partially and after 1seconds of stopping, it let the car move again. It only stopped one of my wheels and then my car was pulled to the other side of the tire that stopped. In my digital car computer, appeared " ESP Fault. VISIT WORKSHOP". I tried to turn off the ESP but i couldn't because the button wasn't working. After this time it happened many other times so i don't know what is the problem. I changed the ESP packet in my baggage. I changed the ABS packet and ABS sensor at wheels. Also I changed the depressor brake pump vacuum. What do you think about this problem? Can anyone help me?

 

The ABS/ESP pump in the front? Very often they can be rebuild, lots of videos around.

 

Is there any history on brake fluid maintenance? I haven’t looked to see if you posted that. If the fluid gets ripe enough it becomes caustic and can melt the seals in an abs modulator.

The same goes for brake hoses. When they gum up inside they can actually retain pressure in the caliper after braking occurs. Just spit balling here to get more info.