Having problems with my air suspension, and at a loss for what to do next:

2005 e53 4.8iS with the intermittent Inactive Suspension message, which I finally diagnosed to a bad passenger side front sensor (using INPA). Soon after the sensor was replaced, the rear driver side started sagging to the bump stop and the rear passenger side would also drop but not as much. The system resets itself sometimes to normal height all around, and at other times gets stuck and be completely inactive.

What should I be looking for? Does the system need to be reset/recalibrated after a sensor swap? Or is this an entirely new problem?

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Thank you,

Samer

2005 X5 4.8iS
1989 635CSi M/T