Hi everyone, this is my first post here

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I’m having trouble calibrating the air suspension on my 2005 Jaguar X350 4.2 V8. My goal was to slightly lower the ride height. I am using JLR SDD v164 (from Aliexpress) with a blue Mongoose clone cable.

The Problem: I followed the common forum method of entering modified values to trick the system into lowering. The process goes almost to the very end, but during the final save, it always throws the following error:
"Fault report Failed to calibrate the air suspension unit. System faults logged Please re-attempt calibration considering the following:

• The vehicle must be on flat, level ground.
  
• Measurements must be made using tool number 204-484.
  
• Measurements must be entered in millimeters."
  

(See attached screenshot).

Current status and steps taken:

• There are no stored suspension (ASM) faults.
  
• A battery maintainer/charger was connected during all attempts.
  
• All doors and the trunk were fully closed.
  
• I tried set to stock settings by entering the nominal values (386mm front / 373mm rear), but the error remains exactly the same.
  
• I've tried calibrating after a long drive, after letting the car sit overnight, and everything else I could think of.
  
• In total, I’ve made about 8 attempts, and it always fails at the exact same final step.
  

Physically, the system seems fine. The compressor runs and raises the car during the calibration process and during normal driving without issues.

My questions: Where should I start my diagnostics? Is this likely a software/cable issue (v164 + mongoose blue clone), or could the ASM be blocking the write for another reason? Could it be a faulty height sensor or a weak compressor, even if they seem to be working during the process?

Any help or advice would be greatly appreciated.

Thanks in advance!

 

Ha! I just went through same thing after CA replacement!
Read message #8 in:
https://www.jaguarforums.com/forum/x...acemnt-295344/
Regular RV charger with 14.6V power supply did not worked
One switching power supply with max available voltage 12.8V 50A did not worked.
I had to raise supporting power supply voltage to 13.7V. Whatch out color for battery and monguse cable in top right corner, If they are are pink or red SDD has problem talking to car.

 

Put a charger to the battery in advance like 15 min.
you got to mesure around the car pretty quick.
often enough it does not work first time.
First you should calibrate on the original values 386mm front 373mm rear centercap to wheel arch. ( the whole system also has tolerances)
lowering means lying to the system (do not do more than 15 mm difference it will probably not accept it) if you have actually have 386mm after initial calibration writ down 400mm then it should lower by about 14mm

 

This way I managed to do it on every car yet. Charger with just 10 amp was sufficient but I started it15min before starting sdd

 

Ok, so I will try again with another charger. Is it important to have all doors and trunk closed during whole procedure? Or it doesn't matter?