Does anyone on here have experience with changing height of sensors for each wheel separately?
I have been trying all day and cannot get them to adjust just the way I want to.
The height is measured from center of wheel to bottom lip of wheel well fender (straight line from center of wheel). It is so for all 4 wheels.
The default height for front wheels is 404mm +/- 10mm (variation in height left to right)
The default height for rear wheels is 406mm +/- 10mm (variation in height left to right)

The closest I get is have one side perfect, and the other about 5mm too low or too high.
As soon as I get into PIWIS2, and make the changes, the sides misalign again, and one side goes too low, while other side goes too high.
Frickin frustrating.

What I use is the LEVEL/PASM main menu in PIWIS2. Then enter Maintenance Repair sub menu. Then select the height sensor calibration sub menu.
While in there, the screen shows all 4 corners, FL, FR, RL, RR, each on separate line.
To make the change, one is supposed to measure from center cap to bottom of fender lip (as stated above). Then you enter value in mm for each corner, then click WRITE, to set the settings into ECU. Then you turn ignition off, then on, then press F12 on screen to finalize the setting. Clicking on write performs write of all values, all at once.
I changed the valve block and refreshed one shock (that was leaking internally). With the new parts in, wanted to make sure all corners are just perfect before I do alignment again.
But this thing is testing my patience.

Some of the questions I have are:
1. Am I even supposed to be using the sensor height calibration menu to set height of each corner separately, or is there different menu where I would code the setting of one wheel for example (the above sets all 4 settings together, with click of the write button).
2. To lower a corner, say by 10mm, I have to be in the menu with all measurements, then I add 10mm to existing number (i.e, if setting for FL is 400, I calculate 400+10 = 410 mm, which is supposed to lower that FL corner by 10mm). AM I doing this correctly?
3. Is there a specific process for the calibration, meaning I have to set the height to predefined height to store in ECU, then make adjustments?

What am I missing? I have been going up and down and cannot get the thing right and hope one of you folks have done this.
I dont get any errors at all, even wehn doing component test before doing sensor calibration. So all my hardware is working properly.

Thanks for help.

 

After replacing the driver side strut and upper control arm a few months ago I had the car aligned. Low and behold my favorite alignment place could not set the camber within spec (too much -). I went again a couple of weeks ago hoping he may be in a better mood or something, still left with too much negative camber.

I never thought to try to adjust with PIWIS, but right now I'm still trying to fix the Windows side of my setup. (Sigh, what a mess)...

 

There are couple reasons why your camber cannot be set just precisely.
1. Once you replace the shock, the bolts holding shock to the body are not precision drilled and still have some play once shock bolts (3), go through the holes. There is still some play in there. One way to correct, would be to look at your camber setting, and determine which way the top of the shock would have to be pushed, towards engine (I believe that would add to camber value), or away from the engine (again, I think this would be decreasing camber). We are talking tenths of one degree here, so moving that shock even 1 mm will result in enough change, to make your measurements fall into compliance.

2. Some of your tires heights are not set just the same. I happen to be doing my height now, after I noticed that there is a slight difference in the height, and as you mentioned, my rear camber changed once I changed height sensor calibration values. So for now I am trying to get my tires just same height, so I can get back to alignment shop and redo alignment again. I bought the lifetime alignment from firestone (about 150 price), which allows me to return there and do alignment as many times as I want, with no charge, for as long as I own the car. I have this on both my Porsche cars, so I can periodically do tire rebalance, rotation and alignment, with no cost. Worth for me.

As to my process, I have been playing with the calibration yesterday, will have to try finish today, since tomorrow is my alignment day, and I am about 5mm lower on one side of car (both tires). Very close, but I want it perfect. We will se how this goes later.

 

OK. After super many tries, I finally have all wheels set at the same height. I actually put the back wheels 6mm higher than the front wheels (spec height calls for rear to be 2mm taller than front), so my back is now 4mm higher. Exactly what I wanted.
Took me all of one day and part of today. Dont ask how many times I recalibrated.

Taking measurements:
All my measurements were from the bottom of the center cap. Why the bottom and not the center of the center cap? Because unless you draw some marks on it, you are not accurate.
My way, I always have a known point of reference, which is the edge between wheel and the center cap. That groove is my reference.
I also know the cap is 76mm in diameter. 76/2 = 38mm. So all my measurements (as I enter into the calibration screen), are whatever the measurement is, minus 38mm. So if I measure 442mm in front, 442mm - 38mm = 404mm (the default spec height of front tires).

Process tips:
- Whatever you do, it is important to complete the calibration at the end (more on this later).
- Get your battery charged up FULLY before you start
- Every few measurements (if you need multiple), say every 3 calibrations, after you complete, start the car and let idle for 3 minutes. It will top up the battery and get it ready for the next set of attempts
- DO NOT LET THE VOLTAGE DROP TO 12V. If it happens during calibration, there is a small risk you can do something to the ECU, and could even brick it. There is a process to build a power supply that will keep the voltage at a constant 12.4V, but if you dont have one, you can still do this but dont spend much time on each attempt (HAVE ALL YOUR MEASUREMENTS WRITTEN, so when you get to the screen, you enter then, double check and save them).
- Enter diags and choose Level/PASM selection, go to next screen but then press F11 to skip diagnostics of entire car (saves batt. power)
- Height sensor calibration is done in the Maintenance Repairs section
- Height entered in mm, and I chose my reference as stated above, so I had to make sure all my measurements are with the 38mm (half of the center cap diameter) subtracted, to give exactly middle of the cap/wheel.
- After you enter all measurements (enter number, press enter key), you save by pressing WRITE (one of the F keys, stated at bottom of screen).
- Then, IMPORTANT, as requested, you must turn the ignition to OFF, then back to ON (if you dont do this, calibration save wont be completed
- After you write and turn ignition off/on, you must get the calibration successful message (check mark on bottom entry of the calibration screen), at which time YOU MUST PRESS F12 to continue. If you dont press F12, calibration will not be completed as well.
- After you press F12, you are done, what I do is exit the screen to main menu of the PIWIS2 tool. Then I turn ignition to off (at which time height will adjust). Regardless, then I turn car on and let idle for few minutes. Compressor will compress air, then suspension will readjust again.

I will be doing a DIY on this one time, process is easy, but is confusing if you have not done it. The above are just some pieces of info I gathered while trying.
I did this with PIWIS2. Easy. I am loving this tool very much. Would not want to be without it now.

 

Thank you for sharing and really appreciate the help on my personal issue. Glad you have it worked out. 👍