SLS inactv got me stumped
 

So, Thought I had the issue licked a while back. But I'll start fro the beginning.
01 x5 4.4 sport with rear axle air.
First got the warning almost a year ago.
Scanned it with inpa, and had a right rear sensor voltage implausible code.
Bought a new one from the dealer and installed it.
No change. Same code.
Looked over the wires, nothing stuck out as bad.
I had a spare module, so I swapped it in and the ride height came up and I thought it was fine. But the inactive warning was still on the dash.
Scanned it again and no had the same code for the left rear sensor. :(
Happened to have a spare one from a parts car so I swapped it in for testing purposes.
No more issues. No warning, codes, all was right with the sls world.
Fast forward 6 months. Bing, sls inactiv pops up again. Codes for the right rear sensor again. This time, since I noticed the sensors are the same, I swapped them. Code stayed the same. Right rear.
I no longer have a spare module to play with.
I tried testing voltage on the wires. Unplugging the module, and testing the yellow/grey wire on the harness, the right sensor has low voltage. .01/02 fluctuating. Sometimes higher if I load the suspension. Left sensor is .07/08 and slightly higher for loaded readings. I'm assuming the issue is the module sees different values and doesnt like it, then turns on the warning.
But I cant seem to find the cause.
The piviot arms are fine. I greased them up to make sure they move freely. The right sensor is new oe (now its on the left side). Module is different (not new, but from a working X). Bags hold air for a long time. Pump comes on when triggered with inpa.
I'm a bit stumped. Not even sure what else I can test/replace.
Any ideas?

check the wires and the sockets, sounds like it just not making contact , those plugs are a PITA.

So bringing this back. Had some time today to look it over again. Still have the right rear sensor voltage code. Pulled everything apart again. Tested wires again. Pin 1 and 2 are supply voltage wires to both sensors. Pin one is left, 2 is right. Both show 5.02 vts. Pin 7 and 20 are sensor signal wires. 7 is right and 20 is left. 20 shows a changing value based on load. Neutral is around 2 vts. Pin 7 is 0 vts. So there's no signal leaving the right sensor. So I tried unplugging the module and the right sensor and ohm'd the wires. Both supply and signal wires have continuity. So it's not a broken wire.
I took the connector apart and looked to see if the pin was damaged. Looks fine. It's tight and appears to make a good connection to the sensor.
I think I'm stumped. Not even sure what else to test.
Any ideas?

This prolly isn't it, but I bought my X5 with that problem.
I replaced a 30 amp fuse in the back passenger side.
Never a problem since.