Land Rover Discovery air suspension problems Explained(+5 Tips)

In this article, we discuss the Land Rover Discovery LR4 Air suspension, the most common Discovery Air suspension issues and tips on how to troubleshoot these to encourage Discovery owners to DIY, save money and continue to enjoy these classic luxury vehicles.

What are the most common Land Rover Discovery Air suspension Problems?

  • Suspension Fault Message
  • Front/Rear Suspension Dropping Overnight

Land Rover Discovery Suspension

The Land Rover Discovery was first introduced as the Series I generation in 1989 and is now currently in its 3rd L462 Generation.

Land Rover Discovery 4 Air Suspension

The Discover 4 L318 generation (2009-2016 model years) was supposedly more robust as compared to the previous LR3 generation. LR4 belonged to the same generation as the LR3 with several improvement updates.

The vehicle dashboard Ride Control switched could raise the Air Springs upto the off-road ground clearance height and lower them back to normal driving height. There was no option to lower the air springs below ‘Normal’ ride height. The lowering could only be done with the help of a PLIP Remote that had the suspension lowering button.

Land Rover Discovery 4 Air Suspension Component Layout

  • The Land Rover Air suspension is also called EAS (Electronic Air Suspension) 
  • The 4 corner suspensions are air struts which do the job of springs, but at the same time, also raise and lower the level of the vehicle, depending on the ride height selected by the driver. 
  • A compressor is connected to 2 Valve Blocks (one each in the front and rear) which supply air to the Air Struts at each wheel.
  • The EAS system maintains the desired ride height by running the compressor to air into the air struts and by compensating for any level difference between the corners by either pressurizing or exhausting air from the individual Air Struts. 

Discovery Air Suspension Components

  1. Front Right air spring damper module
  2. Front Right height sensor
  3. Air suspension control module
  4. Air suspension control switch
  5. Rear Right height sensor
  6. Rear Right air spring damper module
  7. Air supply unit silencer
  8. Rear Left air spring damper module
  9. Air intake filter
  10. Rear valve block
  11. Rear Left height sensor
  12. Upper acoustic cover
  13. Lower acoustic cover
  14. Air supply unit
  15. Reservoir valve block
  16. Air reservoir
  17. Front LH height sensor
  18. Front LH air spring damper module
  19. Front valve block

Discovery 4 Air Suspension Sags overnight

  • Suspension loses height especially after long hours of parking
  • Air suspension control switch inoperative; LED’s off on the button arrows
  • Yellow suspension light on the instrument cluster
  • “Suspension fault” “Normal height only”, message displayed.

Troubleshooting Discovery LR3 and LR4 Air Suspension Sagging Overnight

  • The first thing to do is to diagnose the issue
  • From past experience, this problem mostly throws out the DTC codes C1A2064 or C1A1364
  • These error codes are related to the compressor malfunctioning
  • It is also know from past experience that the compressor can malfunction due to the air dryer being clogged
  • Although replacing the compressor is the best way out of the situation, you could refer to this section on tips on how to rebuild a compressor.

Discovery LR3 & LR4 Fault Message

  • After starting, the ‘Suspension Fault Normal Height Only’ message appears after approximately 30 secs

As seen on Discovery LR3

As seen on Discovery LR4

  • Suspension Warning indicator lights up continuously

Possible Root Causes for Suspension Fault Normal Height message:

  • Within the first 30 secs of start up the air suspension compressor works to pressurize the system and fill the reservoir
  • Hence, the problem is related to the working of the compressor:
    • The compressor not turning on at all
    • The compressor working but in a faulty manner and unable to develop the required pressure
  • The 2 main causes for Compressor malfunction are:
    • Faulty Fuse/ Relay
    • Worn out Air Compressor

Troubleshooting Suspension Fault Message: Air Compressor Fuse and Relay

  • If there is no compressor working noise, then it could be an electrical issue
  • The first thing to check would be the fuse and Relay to the Air suspension system

Troubleshooting Suspension Fault Message: Faulty Air Compressor

  • Before physically removing the compressor, it would be good to read the Fault codes using a Diagnostic Tool
  • If the Fault Code CA120 shows, it means a faulty compressor that is not able to develop enough pressure within a preset amount of time
  • This points to either:
    • A compressor with a clogged Desiccant, or
    • A completely worn out compressor
  • Before you remove the air compressor, as a safety precaution, it is advised to always disconnect the battery terminals. The reason being that the EAS always tries to compensate for any loss of pressure by either exhausting or running the compressor automatically. While working underneath the car, any change in suspension level could be dangerous.

Replacing the Air Compressor Desiccant

  • The  air compressor comes with a desiccant chamber through which all the input air passes so as to remove moisture.
  • The desiccant beads are originally blue in color and become brown over time, finally becoming fully saturated and block the air passing through it.
  • These desiccant beads can be replaced so that the original air flow rate of the compressor can be restored.

Replacing / Rebuilding the Air Compressor

  • Although there are rebuild kits available for the compressor, replacement would be the most ideal solution.
  • Rebuild kits available online would usually contain the Piston rings, Retainer Springs and O-rings required to restore the compressor’s capability to seal air.
  • Apart from the compressor itself, the air filtration unit or air dryer desiccant will need to be replaced. It is always advisable to rebuild the dryer unit also whenever the compressor is being rebuilt.
  • The Desiccant in the air dryer get saturated over long-term use and ends up obstructing air flow and reducing compressor output. It is almost sure that any compressor that needs a rebuild will need a dryer rebuild as well.

Discovery LR3 & LR4 Front/rear Suspension Dropping Overnight

  • After long hours of parking or overnight parking, the suspension height drops at either the front two wheels or all4 wheels
  • Vehicle, once started, is able to lift the suspension to ‘Off-Road Height’
  • Suspension warning light continuous in the Dashboard
  • Loud Compressor Noise due overworking

Troubleshooting Front/Rear Suspension Dropping Overnight: Air Leakage

  • Check and confirm the height of the wheel center from the bottom of the fender before and after parking on each side
  • To check whether the issue is due to a leak, one way, is to
    • Raise the height to maximum or Off-Road
    • Remove the air compressor fuse and leave the vehicle parked overnight
    • This is done to disable the height adjustment mechanism that provides air to the strut from the reservoir
  • If, after disconnection, overnight parking causes a drop in suspension height, then it is most probably due to a leak within the air circuit
  • Leakage can be detected using the Soapy Bubble Test explained in this section.
  • As a Caution, if any leakage problem in the air suspension is ignored the compressor will need to work extra in order to compensate for any loss of pressure in the system. With such overloads, the compressor could eventually wear out prematurely and seize.
  • In most Land Rovers, the most vulnerable position for air leaks would be the air struts.

Troubleshooting Suspension Dropping Overnight: Air Spring Damage/Wear Out

  • Air Spring Damage is a common problem with Land Rovers. 
  • The Air Springs tend to wear out at the top and bottom over time, or they can blow out suddenly when damaged by road debris. 
  • Slow leaks in air springs can overwork the air compressor pump. 
  • The Air Springs usually have a life of 100,000 miles or 6 years in most climates.

Troubleshooting Front/Rear Suspension Dropping Overnight: Valve block Failure 

  • If either both the front or both the rear struts have dropped, then there is a chance that these struts were not supplied air. The Front/Rear Valve blocks are responsible for this supply.
  • Over time, the Valve Blocks could eventually start leaking or could fail to shut off air flow between the individual air struts. A Valve Block malfunction could have been the reason why the front/rear air struts were not getting filled.
  • Valve Block Leakage can be easily detected by spraying soapy water solution 
  • Even if there is no leakage, the Valve block could still be damaged
  • The front Valve Block is on the Right Chassis Rail right behind the Front bumper

Troubleshooting Front/Rear Suspension Dropping Overnight: Faulty Ride Height Sensors 

  • The air suspension sensors in the Land Rover get damaged from harsh weather, dirt or Road Debris. 
  • Any kind of sensor malfunction or failure will make the vehicle incapable of leveling itself. 
  • In addition, the vehicle could get stuck at one particular ride height setting.

Soapy Bubble Leakage Test

  • This is the same procedure to detect and fix a Tire puncture
  • Fill a Spray can with Soapy water in a 50:50 proportion
  • Spray the soapy solution on all the air suspension points where leakage is suspected
  • Observe for Bubbles that form persistently at a particular spot even after you try wiping the foam with a finger
  • These persistent bubble spots are the leakage locations

Conclusion

In this brief article, we have discussed the Land Rover Discovery Air suspension, the most common Discovery Air suspension issues and tips on how to troubleshoot these to encourage Discovery owners to DIY, save money and continue to enjoy these classic luxury vehicles.

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