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Background: Recently replaced both main and auxiliary batteries with new OEM units (DIY). Last year (March), replaced left rear airbag (Arnott), and later the Suspension Air Compressor (Arnott), Valve block (Rapa), and Air Compressor Filter (Mann).
Current Issue: Unable to complete suspension level calibration. Getting "test pre-requisites not met" error.
When attempting to level all axles to -30mm using Xtool (labeled as "normal level" by Xtool), right side sits 1-1.5" higher than left. Additionally, significant voltage variations between left/right axles.
Current readings after attempting to level the vehicle by bringing voltages within 2V-3V range (which coincidentally aligned exterior heights pretty closely as well):
Front Left: 2.82V, 33", -28mm
Front Right: 2.10V, 33.25", -22mm
Rear Left: 2.02V, 33", - 25mm
Rear Right: 3.29V, 33", -46mm
Equipment: Xtool Anyscan A30M OBD2 scanner. Also have a Klein digital angle locator and access to WIS/ASRA
Key Questions:
Is the Xtool A30M capable of performing this calibration?
What parameters should I target before calibration (voltage /exterior height / mm height given by Xtool)?
Are there specific voltage ranges for GLS 450 level sensors?
How can I diagnose potentially faulty level sensors?
Dealer wants $550 for level calibration - trying to DIY if possible. Any guidance appreciated!
Does Xtool tell you what prerequisites are needed? XENTRY will give you that information. WIS/ASRA will not.
Yes, Xtool provides two sets of prerequisites inside the suspension level calibration module and voltages from each level sensor: 1. Vehicle level for each axle, specified range is -40mm to 0mm on all 4 axles.
2. Voltages from each of the 4 level sensors but no range.
3. Incline angles, 4.1 to 9 degrees for the front axles, -1.8 to +2.5 degrees for the rear axles.The Level Calibration Instructions from WIS provide a much tighter range for inclines, which I have been adhering to. Rough incline angles I measured with Klein angle locator were writhing the WIS ranges.
I have reached out to Xtool customer service to inquire for details on prerequisites they maintain in addition to what’s presented to the user (outlined above).
Appreciate everyone’s help with next steps I should pursue.
Hello everyone.
A quick update - I obtained a Launch Creader Elite 2.0 BBA bidirectional scanner. The level calibration module on this scanner seems to work better.
Once I open the module, it levels the car. Even though the mm heights are different, the exterior heights are correct.
However, the level calibration continues to fail, with a similar error message ("test pre-requisites not met").
I would appreciate any guidance and help on how to overcome this.
Thanks again.
hi im in Australia and having the same problem with GLS350d i have the creader elite 2 as well and it states the same as yours in manual calibration mode.
i pumped the car up individually using manual calibrate so i had 820mm to the mudguard from level floor on fronts and 830mm rears
this then gave me 2500 mv on each sensor, so it was level and ride heigh about where i want it, im not sure of standard ride heights or where you measure them from, (the datum lines) can someone please explain if possible?
so that leaves only the angles of the lower wish bones and where exackly you measure the angles on the car?
the range is shown on creader elite to be -1.8 to 2.5 rear and 4.1 to 9.0 front, thats alot of tolerance.
i guess im not imputing the correct angle to get calibration sucessful.
i can use my inclometer app on my smartphone, seems to work ok, but where is this angle measured, its def not the rear half shafts as someone on you tube suggested, there far greater angle than 2.5 deg, so i think its the bottom wishbone, buts its all bumpy and no flat area to sit the phone? any help would be appreciated, dave
My problem with level calibration is resolved!
I suspected the level sensors were defective. Ordered new ones but when I got ready to replace them, I noticed that the ball joint on the rear left link rod (arm) that connects the the level sensor was worn out badly. This essentially led to incorrect/inconsistent readings on the sensor.
I ordered a pair of link rods. Part numbers are 166-320-09-32 (rear left) and 166-320-10-32 (rear right). Here is a short video comparing the old and new link rods side by side. Below are a couple of pictures in case video cannot be uploaded/accessed.
I replaced the link rods on both rear sensors. Afterwards, I was able to complete level calibration by entering 5.2 degrees for front axles, and -0.7 for rear axles. I used XTool AM30 dongle and mobile app to complete the calibration. It has been 2 weeks since I completed this and all seems good so far.
Wha's interesting is that in some videos/resources I had seen, bending of link rod was mentioned as a possible issue but I do not recall seeing an issue with the ball join on link rods. Hope this helps someone else with a similar problem.
NOTE: I first attempted to complete level calibration using Launch Creader Elite 2.0 BBA (with the same inputs as above) but for some reason it wasn't able to complete the procedure. it could very well be a user error.
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2017 GLS 450 Suspension Level Calibration Help Needed
