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Overspeed600
6th August 2024, 03:07 PM
I’ve always managed to fix most problems via general searches but the D4 EAS finally has me stumped…….
No faults displayed on the GAP IID Tool but suspension wants to auto raise to Extended after being commanded to Standard height and would indicate as an underbody obstruction even though on a workshop concrete slab:
Here’s the symptoms in no particular order,
*Rear bags deflate way too slowly whether it be:
>using dash Lower button or
>using GAP IID Lower command or
>using GAP IID Deflate Corners command
*Commanding Standard by any above method results in initial front lowering followed by all 4 corners raising to extended
*Standard height calibration sometimes allowed, sometimes not, always resulting in previous symtom when height change to Standard commanded
*No EAS faults logged
*Rear axle raise test = Raise OK
*Front axle raise test = Lower(?) then Raise OK
*Have witnessed Live Values showing FL and FR reading back to front as in L=R values with R=L values (this one is truly bizarre)
Have replaced AMK comp with a new AMK comp and checked and flashed ECU
Have replaced all corner position sensors as FR was always reading a (-) value in Standard, so does the new sensor……….(wiring loom damage adding additional electrical resistance??)
Have confirmed all compressor valves operate correctly
Have replaced all O rings on all three valve blocks
Have checked clear airlines, wiring, plugs, etc
Have checked all bags for leaks - All OK

Have not yet physically removed the ECU as that looks like a real mission but is likely next

Have found similar issue posts online but their fixes have always been what I have already done/checked/replaced.

Any ideas?

Cheers.

BradC
6th August 2024, 07:05 PM
Have you measured the calibration or attempted to re-calibrate? Especially after replacing the sensors.

Eric SDV6SE
6th August 2024, 07:27 PM
+1 for the calibration being the issue.

To me the car is trying to autoleve, and is operating within the ranges allowed, hence no error codes. I used the Rovacom VCIQ on my D4 for years, and this allowed you to reset each corner to within a mm of each other by setting the right offsets per corner.

I'd suggest to reset the calibrations and start from scratch, or if that's not working, change the offsets at the front to stop it raising to extended mode, them getting the offsets correct fir each. It's an iterative process and you need to measure from a flat surface (garagevfloor) to middle of the wheel arch, write them down to work out the offsets.