I have a problem with air suspension of my BMW X5 4.8IS 2005. I had error "selflevel susp.inact". I noticed that rear axle was low, but not drastically. I connected to the computer and IMPA error says this:
RESULT: 2 errors in error memory !
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116 Speicherdruck bleibt konstant, wenn Speicherfuellen angefordert wird
Error frequency : 1
Kilometerstand 197160.00 km
Batteriespannung 13.63 Volt
Speicherdruck 12.75 Bar
Balgventil vorne rechts 0.00 0/1
Balgventil vorne links 0.00 0/1
Balgventil hinten rechts 0.00 0/1
Balgventil hinten links 0.00 0/1
Speicherventil 1.00 0/1
Ablassventil 0.00 0/1
Kompressorschalter 1.00 0/1
Hochdruckablassventil 0.00 0/1
Crosslinkventil hinten 0.00 0/1
Crosslinkventil vorne 0.00 0/1
Kompressortemperatur 8.00 Grad Celsius
Fahrzeuggeschwindigkeit 2.00 km/h
durchschn. Fahrzeughoehe -1.00 mm
Plausibilitaetsfehler
Fehler momentan vorhanden
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50 CAN Bus
Error frequency : 1
Kilometerstand 197160.00 km
Batteriespannung 14.25 Volt
Speicherdruck 13.00 Bar
Balgventil vorne rechts 0.00 0/1
Balgventil vorne links 0.00 0/1
Balgventil hinten rechts 0.00 0/1
Balgventil hinten links 0.00 0/1
Speicherventil 0.00 0/1
Ablassventil 0.00 0/1
Kompressorschalter 0.00 0/1
Hochdruckablassventil 0.00 0/1
Crosslinkventil hinten 0.00 0/1
Crosslinkventil vorne 0.00 0/1
Kompressortemperatur 9.00 Grad Celsius
Fahrzeuggeschwindigkeit 0.00 km/h
durchschn. Fahrzeughoehe 1.00 mm
allg. Fehler
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I removed those two errors. Removed key and started engine again. Then I connected with ISTA-D. I regret that I haven't connected with ISTA-D before I removed errors. Anyway, I checked and I have readings from all level sensors.
Car is parked on the side of the road so I think that difference is ok.
Air pressure and temperature of compressor.
Volate of the system:
I checked all air bags manually, and they seems to be good, have pressure and no leaks.
I started to play with air suspension buttons - the one beside steering wheel. Pressed air suspension button to go to level "high", front axle went up, rear axle didn't. Pressed that button to go to "middle" level. It started to blink, and then front axle went down. Then I pressed that button to go "high" again, started to blink, nothing happened, I pressed it up/down many times, I waited about 1-2minutes every time between pressing buttons, and at one point, immediately after the press of a button front and rear axle went up within 3 seconds. Then I wanted to lower it but it was impossible, button was blinking in the middle and nothing happened.
During clicking of that buttons up/down I constantly read/watched the state of valves, if they are opened, etc. So in that event when my suspension went all up, all of them opened and then closed. Below picture:
So I wanted to lower it so I triggered few times "lower front/rear axle" using ISTA-D, until the proper level I want to ride was set. During that I triggered lower and higher options for front/rear axle. All worked just fine.
From the translation I know that it can be relay in the compressor(compressor switch) and memory valve(whatever it is) - but these are only my guesses.
I have a reading of 15 bar pressure in these air container.
Does anyone knows what should be the right pressure there? maybe compressor is trying to pump air but compressor valve is not always opening so no air is getting to air container and compressor switch is faulty?
Maybe I need to replace the main control unit? but readings shows that it is in good condition.
Does anyone know what these errors can be? and what should be replaced based on the symptoms I described - basically not responsive button behind steering wheel?
Thanks for any help/hints.