06-25-2020, 09:37 AM | #1 |
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Puzzling Air Suspension Issue
hey folks - I have a 2015 BMW x5 with 3rd row. Having an issue where the springs only sag once the car is started.
About 8 months ago we had sagging suspension on one side, had both air springs replaced and it was fixed. Recently I've been noticing that air suspension sags only when the car is turned on. It goes like this:
The only time this doesn't happen is if I run into a store for less than 10 minutes. Otherwise I need to do the whole song and dance each time I turn the car on. So - it doesn't seem like the bags are leaky. Is there something wrong with my compressor? Is a sensor confused? It seems the opposite of everything I've found online where it sags when parked. Mine only sags when started. Worth noting that I think this started about 2 weeks ago when we towed a 12 foot enclosed trailer. |
06-25-2020, 10:40 AM | #2 |
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I'd look at the level sensor first. Verify it's connected first. And if you have a multimeter, check the resistance of the sensor and make sure it's linear as you move the arm. Car might think suspension is way up, triggering deflation.
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06-25-2020, 10:57 AM | #5 |
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just checked it - both seem on tight and no frayed wires. Don't have a millimeter with me right now but can check once I do. Just unbolt the arm and move it up and down myself while checking resistance?
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06-25-2020, 12:13 PM | #6 |
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Pull the connectors out and check for corrosion. I'd lean more towards a wiring issue honestly. But yes, just hook up a meter and move arm up down slowly.
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06-25-2020, 02:26 PM | #7 |
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Your compressor may need the desiccant changed. Mine was deflating sporadically, so I replaced the airbags and changed out the desiccant balls in the compressor as well. All of it took and hour and a half start to finish.
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06-25-2020, 02:49 PM | #8 |
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I saw that video and was wondering if it was my issue as well but mine isn't doing it sporadically, just when I turn it on.
Might try it though as it's a cheap fix. Do I need to jack up the car to get at the compressor? Or can it be done on the driveway? |
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06-25-2020, 07:27 PM | #9 |
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I took one of the connectors off, and it looks totally clean. Now I can't for the life of me get it back on. I can't press it hard enough to get it over the two barbs on either side.
Anyone else have this issue? Any tips? |
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06-25-2020, 07:42 PM | #10 |
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The connector usually have to be oriented a certain way. You by chance bend a pin inside?
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06-27-2020, 03:09 PM | #13 |
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Did it in the driveway on ramps. One cover to remove to gain access to the pump. Mine was sporadic and oddly would occur in the same location/places; twice at the gas station and twice at the same restaurant, a few times in the driveway. It hasn't happened since the repair.
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06-29-2020, 08:11 AM | #14 | |
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got the clip back on - had to bend the side prongs in a little bit so they would catch.
Quote:
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06-29-2020, 05:12 PM | #15 |
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Yes, front wheels. Should be pretty easy. Keep track track of where connections and tubes were taken off with a phone pic.
I also used BimmerLink to clear all faults. |
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07-04-2020, 03:24 PM | #16 |
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So I replaced the silica balls this weekend - they were totally saturated and there was moisture in the chamber. Slapped it back in, it went up as it always does when it’s totally flat. Drove it around all day.
Parked it for 24 hours, stayed up as it always does, turned it on and it went right down flat again. Locked it, walked away with the key for 2 mins, came back, turned it on and it pumped right back up again in ~25 seconds. So - that was worth doing, but not the issue. So weird that after sitting fine for more than 12 hours, it will always go down as soon as I start the car. Any other suggestions? |
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07-04-2020, 04:56 PM | #18 |
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Usually yes. I have only left it for ~10 mins though.
I sometimes get the “chassis function restricted” error but it goes away when it pumps back up. Is there a code I need to clear after this comes up? On board UI doesn’t show anything |
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07-04-2020, 05:09 PM | #19 |
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I'm leaning towards a sensor or wiring issue.
See this thread for example. https://f15.bimmerpost.com/forums/sh....php?t=1550757 |
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07-05-2020, 09:11 AM | #20 |
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Thanks - the error in that post is what comes up when I unplug the sensor.
Some more info: Today it pumped back up all the way after dropping. Maybe a few mins. I got bimmerlink and these are the errors that show up. They don’t come back immediately after clearing. I also replaced the relay in the car. Finally, it seems like I can hear the bags filling on each tire even after it’s been fully up. So that leads me to think it’s either the sensors not knowing they are fully up, or the solenoid on the compressor stuck open. |
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07-07-2020, 12:59 PM | #21 |
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Cleared all the codes, waited a day and turned it on.
Same thing - it dropped totally and did not re-pump itself. Threw the code 480DB0 which is "Raise the control time". Taking too long to pump up. Did the same lock + walk away. Came back and it pumped up again. Cleared the codes and nothing has come back. I can hear the compressor kick on and off, so that makes me think the height sensors are working... Could it be a relay? I'm so very close to just ordering a new compressor and being done with it. I just want to be reasonably sure it will fix the issue. |
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07-07-2020, 01:12 PM | #22 |
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