Air suspension

Joe Diagnostician Midland, Texas Posted   Latest  
Question
Chassis
2009 BMW 535i xDrive 3.0L (N54B30A) 6-spd (GA6HP19Z)—WBAPT73539CX02618

hello diag​.​net I have a 2009 BMW 535i. a fellow tech replaced air compressor both rear sensors. The suspension goes flat on right rear while driving the vehicle. I checked for proper voltage at the ride hieght sensors as well as both left and right signals which read opposite of each other (not sure if this is normal) I’ve checked for leaks found none but something is commanding the right rear side to go down as I drive the vehicle. has anyone worked on this vehicle with the same issue?

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Stephen Owner/Technician
Orange, Texas
Stephen Default
 

Lift the rear up and extend the air spring. Check lower air spring where it makes contact with lower mount. You may find micro cracks in the air spring. Hope this may help.

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Agree
Genaro Owner/Technician
Hollywood, Florida
Genaro Default
 

Pretty sure I could be in transport mode had the issue last week on an x but I had a fault code for it did you check for codes

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Dimitry Owner/Technician
Leesburg, Florida
Dimitry Default
 

I had this happen to me on a gt 535 was a bad valve block. If you take the air lines from valve block and change hose sides from left to right and so on does conditon follow on oppiste side ? If so you may have faulty valve block. Ive seen mount for bladder brake from bottom .

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Lew Owner/Technician
Monroe Township, New Jersey
Lew Default
 

I also have seen the solenoid valve block do that.

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Andy Diagnostician
Toronto, Ontario
Andy Default
 

What's the history? Body shop car, regular customer always drove the car and one day it went down? If regular customer I would first run a ride height calibration. This will identify any components not operating correctly. If it completes the calibration successfully at least you'll know the systems happy with all components. Start their IF no storied history. Minor leaks would be compensated…

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Jose Technician
Woodland, California
Jose Default
 

What doe s scan data say for ride height ? You mentioned you checked for proper voltage ag the sensors and they are opposite left to right. What is the control module interpreting this as? Answer should be in millimeters.... Was a calibration or startup function carried out after sensor replacement? Ride height calibration is important on these vehicles....

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Joe Diagnostician
Midland, Texas
Joe Default
 

hello I have limited data using the autologic blue box I don't have a data parameter for the voltage signals at the ride height sensors but you make a great point I’ll try a different scan tool and see if it has the coverage. this vehicle is equipped with a single axle rear air suspension and came in flat on the rear. another tech Diagnosed it and replaced the compressor assembly and the valve…

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Jose Technician
Woodland, California
Jose Default
 

Joe all the procedures you have performed seem ok, but since youre at the point of pulling your hair out. lets take a step back and see what the computer is trying to do. We need scan data of ride height measurements. Lets start with some data and see if we can figure it out. Also i have seen before the plastic airlines installed incorrectly to where they are pinched shut and dont allow…

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Joe Diagnostician
Midland, Texas
Joe Default
 

Thank you! I’ve left the shop for the day but I will get you the data you ask for Monday. I swapped the air spring from right to left and it still goes flat on the right performed a visual inspection on the lines and all the air suspension components as well as sprayed with soapy water no leaks found with the system pressured up the vehicle does not go flat if I leave it in the bay overnight at…

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Joe Diagnostician
Midland, Texas
Joe Default
 

good morning this is the data I have using the drive pro the Voltage level is strange 7500mv ?

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Jose Technician
Woodland, California
Jose Default
 

not concerned about the voltage right now, your deviation from normal ride height is 83mm. i like it to be under 10 mm. can you carry out a ride height calibration. you will need a tape measure that reads in MM. you will need a scan tool that has the ride height calibration function.

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Joe Diagnostician
Midland, Texas
Joe Default
 

Hi, I successfully performed the ride height adjustment on this BMW using the autologic but I was unsuccessful in correcting the issue. I swapped the air spring from right to left in an effort to condemn the air spring I then performed another adjustment and drove the vehicle it now goes down on the left. I installed a new air spring on the left and performed another adjustment I then drove the…

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Joe Diagnostician
Midland, Texas
Joe Resolution
 

i finally got this one fixed I wish I would have found it much sooner but I guess you can’t win them all. I replaced the The electronic height control unit and i performed a ride height adjustment and then road tested the vehicle. finally the vehicle is fixed it no longer goes down. it stays at normal ride height something must have been wrong in the inter grated circuit I’m not sure but I lost…

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