BMW X5 Air Suspension Issues Explained(+5 Tips)

In this brief article we are going to discuss the different BMW X5 Air Suspension problems, what the causes are, and their troubleshooting Tips.

What are the most common air suspension issues in a BMW X5?

The most common BMW X5 air suspension issues are:

  • Rear End Sagging
  • Level Control Error Message in X5 E70
  • Suspension Error Message in X5 E53
  • Chassis function Message in X5 F15

BMW X5 Suspension Set-up

The X5 is BMW’s mid-size crossover luxury SUV. It was launched in 1999 on the E53 chassis platform in the first generation of X5 made upto 2006. The subsequent platforms of the X5 were E70, F15/F85 and G05.

In the X5 Platform, the Front suspension set-up is a Double Wishbone set-up with a coilover Strut. There are 2 separate Lower Control Arms and therefore 2 Lower Ball-joints for wheel Spindle with a Torsion bar & coil springs. 

The Rear suspension of the X5 is a 3-link independent suspension (lower control arm, Upper control arm and a Toe control arm) with Torsion bar & coil springs. The lower control arm was a 2-in-1 link with 2 bushing joints to the subframe and for this reason the trailing arm was eliminated.

In the E53 generation, 2 versions of self-leveling air suspension were available as an option in certain model years. The 3.0 and 4.4 models were offered with the optional EHC II (dual axle Self Leveling Suspension or SLS) from the 2002 model year onwards. In the E53 4.6is only the rear SLS (or EHC) was offered as an option. The rear suspension would have the same layout as the standard suspension, but with the coil spring replaced by an air spring.

Rear end Sagging

  • Rear suspension loses ride height completely
  • Driving in this condition feels like there is no suspension
  • For the X5 F15 generation air suspension, often times, there are no error codes generated for the rear end sagging condition

Root Causes:

  • Rear air suspension sags due to loss in air pressure
  • The air pressure loss could either be due to 
    • A failed compressor, or
    • A leakage in the air suspension system
    • Malfunctioning Valve Block

Preliminary observation:

  • First make sure the car is unloaded and parked on a surface with no slope.
  • Now measure the vertical distance from tire top to the bottom of the fender on the sagging side as well as the non sagging side
  • If there is a difference of more than 15mm between the left and right, then there could be an issue

Troubleshooting Rear end Sagging

In the event that you are not able to get diagnostic trouble codes (DTC’s), the next possibility is to perform 4 Basic EHC (Electronic Height Control) troubleshooting steps available in “Service Functions” under the “Chassis and Suspension” module in the ISTA Diagnostic tool. They are:

Check for Compressor Turning on

  • You need to hear the pump turn on. This will check our EHC functionality.
  • First listen to see whether the compressor turns on 
  • If the compressor does not turn on there is a high probability that the compressor fuse might be blown
  • Check the compressor fuse (orange 40A fuse) within the fuse box located under the dashboard in the glove box
  • If the Fuse is blown it most probably means that the compressor has failed
  • In a majority of cases, the car will be unable to raise itself, even if the compressor runs. You can easily check by replacing the Relay and the Fuse and seeing whether 
    • There is compressor working noise
    • The suspension starts to raise

If this fails to happen, then it is almost confirmed that the issue with the compressor

Filling and Draining Functional test :Valve block check

  • Remove the air connector at the Air Spring and perform ‘fill procedure’. 
  • This will check for air flow from the compressor through the valve to the spring. 
  • The air-line is easiest accessed at the spring instead of the valve. 
  • While checking the valve block, notice whether you hear Air Flow out of the air line at the air spring? If YES, then it means that the valve block is functioning properly. 

Filling and Draining Functional test:Compressor Check

  • The disadvantage with the X5 F15 generation air suspension was that it did not have an air reservoir and a pressure sensor to monitor the pressure generated.

But if you wish to check compressor air pressure, you can either:

  • Use a manual gage and adapt it to the BMW air compressor’s air connector fitting
  • Use an electronic pressure sensor from another device using an adaptor to the BMW compressor’s air connector fitting. Here you will need to use a pressure reading interface and software application to get the readings on a Laptop.
  • The pressure must go beyond 22 bar. If not, it means that the compressor has failed.
  • Although compressor replacement would be the best option, you could try rebuilding the compressor after reading this section.

Pro-Tip:

  • Replace the compressor in your suspension system
  • You will need to test whether the new compressor responds to the system

For this you need to access the Air-suspension control unit located behind the rear seat inside of the trim panel

  • Once you access the fuse-box, reset the air suspension by pulling out and refixing the red 10 Amp fuse.
  • Once the reset has been done, if the compressor works properly, it will cause the rear suspension to rise in height.

Filling and Draining Functional test: Air Spring Check

  • If there is loss of suspension height in spite of a properly working air compressor, then the air leakages could be the next thing to suspect.
  • Air leakage related suspension sagging generally is seen when the car is parked overnight and sometimes even over a period of days.
  • Air springs are known to wear out and crack at the rubber bellow surface gradually after accumulating mileage. They generally would last 70K to 80K miles depending on usage
  • In a high mileage vehicle, the air springs would be the first place to check for leakages.
  • Repeat the fill procedure explained earlier. Then spray springs with soap solution to check for leaking.
  • After spraying the soapy water solution, wait to see if there are whilte foam bubbles that stay at one spot even after wiping it with a finger.
  • In cases where the leak of major, you even hear hissing noise coming from the leakage point and be able to locate it by ear
  • Before removing the air spring for replacement, be sure to relieve the air pressure from it at the valve block, which is located in the underbody on the passenger side.
  • Relieve the left or right air spring valve by loosening the connector gradually. If this is done suddenly, then you could damage the O-rings within the air connector.

Pro-Tip:

  • Aftermarket replacement bellows tend to give a higher service life as compare to the OE parts
  • Some aftermarket parts also come with a lifetime warranty instead of limited warranties offer by BMW

‘Level Control’ Error Message in E70

  • When turning ON the ignition the center console displays an error with the ‘Level Control’ system
  • This error applies to the BMW X5 E70 generation

Root Causes:

  • This error is mostly coming from the circuit concerned with sensing the ride height
  • If the ride height reading turns out to be outside of the system preset limits, this error will show
  • The reasons for this happening are many since the fault could be due to any component in the circuit

Troubleshooting ‘Level Control’ Error Message

  • In a Diagnostic tool, Go to the module EHC (Electronic Ride height Control) and look for the error codes
  • Look to see if the fault is detected at any particular corner as the source of error
  • Visually inspect the particular corner sensor underneath the vehicle
  • See whether the connections are corroded
  • If the connections seem OK and still there seems to be an error, it might be the sensor itself that is defective
  • In order to confirm this, replace the sensor then check if the error persists.

Suspension Error Message

  • When turning ON the ignition the center console displays an error saying ‘Suspension Auto-Level Inactive’
  • Air suspension stops working
  • Vehicle is in limp-home mode and cannot be driven

Troubleshooting Suspension Error Message: Compressor Fault

  • Firstly, See whether the connections are corroded
  • If the connections seem OK and still there seems to be an error, it might be the sensor itself that is defective
  • In order to confirm this, replace the sensor then check if the error persists. If it does then further investigation using a diagnostic tool is necessary
  • In a Diagnostic tool, Go to the module EHC (Electronic Ride height Control) 
  • Among the available “Data Streams”, select the Air suspension accumulator pressure sensor to see if it is accumulating the correct pressure
  • Start the vehicle and see how much pressure builds up within a span of 1 minute
  • Ideally, the pressure should build up to a minimum of 22 bar
  • If this pressure level is not achieved then it seems that the compressor has worn out and either needs to be rebuilt or replaced
  • Although the recommended repair procedure is to simply replace the compressor assembly, there is a possibility to rebuild your air compressor. See this Rebuild procedure for details.

Troubleshooting Suspension Error Message: Ride Height Sensor and Control Module fault

  • Diagnostic tools shows DTC (diagnostic Trouble Code) ‘Ride-Level Sensor’ Front/Rear Left/Right’
  • Inspect the particular corner ride level sensor to check for physical damage or corroded connectors or any broken wiring
  • Replace the sensor/connectors where necessary and diagnose once again
  • If the error still persists, you need to check the ‘Data Stream’ for “Deviation ride level, front/rear right/left”, which is basically a reading that tells the ride height value that the sensor is reading at each suspension corner
  • Zero value means that the sensor signal is not reaching the control module. If the sensor has been replaced and connectivity voltages are already checked, then it could be an issue with the Suspension Control Module (EHC II) circuit itself.
  • You confirm this by swapping the left and right side sensor at the ‘Zero reading’ side and once again check the diagnostic ‘Data Stream’. If you get the same zero reading on the same corner after swapping, it means that the sensors are working and that either:
    • There is an issue with the wiring between the sensor and the EHC II control module, OR
    • There is an issue with the EHC II control module circuit itself
  • You can access the circuit diagram using the Diagnostic Tool interface for each sensor and troubleshoot the continuity in the connection interface by using a probe and shorting the appropriate electrical signals
  • If it is confirmed that there are no issues in the wiring, then the only variable left is the EHC II Control module.
  • The suspension control module is located underneath the glove compartment

Chassis function Message in X5 F15

  • Center console displays a ‘Chassis function Restricted’ Error
  • Rear of the vehicle Sags
  • Explained as seen on the X5 M Sport option vehicle of F15 generation
  • Loss of ride height points to a loss in air pressure due either:
    • A leakage somewhere within the system
    • Compressor not able to generate pressure due to malfunction

Troubleshooting Chassis function Message in X5 F15: Leakage

  • First and most vulnerable area of the suspension is always the Air Spring rubber bellows which are prone to wear and tear. Once the bellows wear out, they tend to crack and develop holes while developing into leakages.
  • The next leakage point to be checked is the Valve block or Solenoid valves that distribute air pressure to the individual air bellows. The connector necks are potential leakage spots when the connector O-rings would have worn out.
  • A leakage can be detected using a soapy water solution spray. Spray this solution at the area of interest and observe how the foam sticks to the surface. If there is an air leak, the foam sticks to that point and comes back even if you wipe the foam with your finger.

Troubleshooting Chassis function Message in X5 F15: Air Compressor

  • The Error message points to the fact that the air suspension system does not have enough air pressure to be functional.
  • The loss of pressure could also be due to a malfunctioning air compressor
  • Air compressor malfunction happens due to a variety of reasons. The two major causes are:
    • Internal wear of either the piston or cylinder does not allow the production of pressurized air since it has lost the ability to seal air on one side of the piston
    • Blockage in the internal air dryer mechanism that restricts the flow of air
  • In both of the above cases always use a Diagnostic tool to check what is the air pressure generated by the compressor
  • In the EHC module, read the ‘Data Stream’ for Reservoir pressure. For a properly working compressor, the generated pressure should be at least 22 bar. Any reading below that means an internal issue with the compressor.
  • Although the recommended repair procedure is to simply replace the compressor assembly, there is a possibility to rebuild your air compressor. See this Rebuild procedure for details.
  • Once the compressor has been replaced, repeat the air pressure sensor

Conclusion

In this brief article we have discussed the different BMW X5 Air Suspension problems, what the causes are, and Troubleshooting Tips.

How do I Rebuild my BMW Air Suspension Compressor?

  • This applies to all generations of BMW X5 and X6 F16 generation
  • To check for compressor issues, you need to dismantle it and check the Piston, Cylinder and Piston ring condition. Ideally, the piston rings must have elasticity
  • The best course of action would be to replace the compressor, but for economic reasons, you could also try using a repair kit (Piston and rings) to rebuild the compressor. 

The rebuild option does come with risks as there could be issues in the compressor other than just the piston and rings.

  • The compressor has an Air Dryer integrated in the same assembly. This Dryer is filled with Desiccant Granules
  • When the desiccant granules have reached their moisture retention capacity, they expand and leave no room for the air to freely pass through, leading to a partial blockage.
  • When new, the granules should be Blue in color. They gradually become brown over time. If they turn completely brown, it means that the granules have fully saturated.
  • The desiccant granules are replaceable and can be easily done

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