EHC2 dual axle air suspension - bad module?

[SocalD]

Hey all - I have a 2005 X5 4.8is with dual axle EHC2 air suspension that has the infamous "SELF LEVEL INACT" dash warning. And the problem is the pump will not turn on. I have already used both DIS and INPA to attempt to manually turn the pump on. While it shows the function was activated, the pump is not running. And I have checked both relays related to the pump; the purple one that is on the fuse/relay block behind the rear right removable panel, and also the black one that is hidden underneath the battery tray cover that is wrapped up in protective foam. I have also checked the pump by removing it's power PINs and hooking up 12V directly to the leads which the pump turned on and ran just fine. So the only thing I have not checked is the air suspension controller/module. Is there any way to verify that is working properly?

The only other clue I can give you is that I just finished a major repair in which the car sat for 4-5 weeks with the battery disconnected. I was repairing the damn alternator bracket gasket that was a nightmare but got er done!

[andrewwynn]

This will happen if the reading is out of tolerance on a wheel height sensor.

Confirm all your sensor arms are horizontal and the bar to the control arms are vertical. They can get flipped when the wheels are at maximum extension when the car is on a lift.

I see about once a year on xo. Fingers crossed you're the 2024 quota.

[EODguy]

Originally Posted by andrewwynn

This will happen if the reading is out of tolerance on a wheel height sensor.

Confirm all your sensor arms are horizontal and the bar to the control arms are vertical. They can get flipped when the wheels are at maximum extension when the car is on a lift.

I see about once a year on xo. Fingers crossed you're the 2024 quota.

I hope that's it for the OP, although I am disappointed nobody else has Zamboni'd it.... I mean I'd feel a little better if ANYONE did...

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[andrewwynn]

I *definitely* thought about exploring that setting. More than once. I owe you for saving my bacon by trying it before me!


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[EODguy]

Originally Posted by andrewwynn

I *definitely* thought about exploring that setting. More than once. I owe you for saving my bacon by trying it before me!


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I am hoping to continue to be an example to many...


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[SocalD]

Originally Posted by andrewwynn

This will happen if the reading is out of tolerance on a wheel height sensor.

Confirm all your sensor arms are horizontal and the bar to the control arms are vertical. They can get flipped when the wheels are at maximum extension when the car is on a lift.

I see about once a year on xo. Fingers crossed you're the 2024 quota.

Thanks Andrew. So this is strange but after re-installing the pump and reconnecting everything, the pump decided to work! Interestingly, you mentioned the level sensor getting flipped. I had to remove one of them to do the repair I mentioned earlier but it was installed correctly. I will have to remember that one though. What is odd though when using DIS, 3 of level sensors show between 1.5-1.8V approximately. And the 4th one is something like 3.8 and the car is perfectly level and calibrated. Sounds like one sensor might be going bad and is right on the threshold of being out of spec.

[andrewwynn]

It's very strange for one to read crazy different. I think I'd find what three range it can work though and replace if it's right at the edge. It's possible if it's the same part any used upside down it would have a high voltage and sweep low but I would be very surprised so definitely investigate