Lateral and Transverse Acceleration Sensor live readings

[jdog1woof]

Hello all,
I have searched high and low for this information, and have come up short, so please feel free to point me at a thread if you believe it exists. I have picked up a poorly maintained 02' Z3 roadster I am trying to nurse back to health. The car has the DSC and amber brake light lit. I have found using my Foxwell scanner with BMW software that the system has set 5E26 (ABS-DSC Control Unit Voltage Supply, sensors), 5E30 (ABS-DSC Transverse Acceleration Sensor), and 5E38 (ABS DSC Rotation rate sensor). I am somewhat familiar with the system, so started by checking fuses (though all seemed fine), then moved to remove the drivers seat (US car with LHD) and pulled back the carpet. I did indeed find moisture in the footwell where the sensors live. Both have clearly been wet and are presumed junk. I have ordered two replacement BMW units (used). While I wait, I am checking some other things and ran some live data to see what I could see. I was hoping the forum knowledge could help me with two things: 1) I am trying to determine what my live data at a flat stand still SHOULD BE for when the car is running, sitting still, for both of these sensors (right now, the Foxwell reports the transverse sensor reading at 2.57G and rotating speed at 93.88). I would think both should be 0, and guessing these are maxed out values. My second question is does anyone know what the values should read on live data when the sensors are unplugged (and the circuit is thus wide open).

any help is much appreciated.

 

[colb]

Might be worth trying to recalibrate the steering angle sensor to see if that resets the yaw sensor as well as they are all connected with each other. Should find the reset in the menu on decent scan tools.

 

[jdog1woof]

Might be worth trying to recalibrate the steering angle sensor to see if that resets the yaw sensor as well as they are all connected with each other. Should find the reset in the menu on decent scan tools.

Thanks for the suggestion! I did that this morning and it re calibrated successfully. I observed in live data that the readings travel in accordance with the wheel turning and stabilize at or very close to 0 at dead ahead, so I believe that is working. The other sensors still remain at fixed very high values mentioned in original post. I will wait for replacements to arrive and report back if there is any difference. Part of what I’m wondering is if the abs module itself is having issues. I would think there would be some difference in live data when the bad sensors are plugged and unplugged. If anyone knows what the expected behavior there is it would be good to know.

 

[Stevo7682]

This unfortunately will only be able to gain assistance from mainly late model owners as all earlier z3 only have asc so no steering angle sensor no yaw sensor different type of abs sensor no pressure sensor on master cylinder.
Certainly getting the yaw sensor wet generally not good dont know what abs pumps are like on dsc cars i know the asc pumps can have solder joint issues internally also know pumps fitted to e46 with dsc problematic
New parts are ordered logical step to start from there .
Take all water ingress issues have been dealt with.
Stephen.


Stephen.

 

[jdog1woof]

This unfortunately will only be able to gain assistance from mainly late model owners as all earlier z3 only have asc so no steering angle sensor no yaw sensor different type of abs sensor no pressure sensor on master cylinder.
Certainly getting the yaw sensor wet generally not good dont know what abs pumps are like on dsc cars i know the asc pumps can have solder joint issues internally also know pumps fitted to e46 with dsc problematic
New parts are ordered logical step to start from there .
Take all water ingress issues have been dealt with.
Stephen.


Stephen.

Thank you for the heads up. Makes sense that it’s a less common configuration (I hadn’t thought of that)

 

[jdog1woof]

In the spirit of making this thread useful to someone someday I’m going to try and keep this one up to date. Today I tested to see if the harness was powered to those sensors. I found that for each (both are 3 pin connectors) that the center wire is the common and the right wire (looking down at the face of the connector) is the reference (got clean 5v at both of these). I hooked up my scanner to get live data off the sensors. When I supplied power from the reference to the signal on each connector I observed the rapid change in value on the live values (so now I know both sensors get power and that the DSc is capable of receiving a signal over the signal wire. As a result I believe the answer to the original question is that at open circuit (sensors unplugged) on live data you will see 2.57g and 93.88 on the transverse and lateral acceleration sensor circuits

 

[jdog1woof]

Well after much poking and prodding a new transverse acceleration sensor and lateral acceleration sensor and a relearn procedure on everything and DSC is back in business.

 

[Pingu]

I expect to see a video with some live data overlays

This was my attempt with VANOS...

 

[jdog1woof]

I expect to see a video with some live data overlays

This was my attempt with VANOS...

I am super impressed by this! Love the overlay