Photo: RR in Access Mode (Official Land Rover press photo) What to do if it sinks to this state when we don't want it to!

Overview

This page summarizes the most common EAS problems faults reported to me by owners, or ones that happen frequently enough to be acknowledged by Land Rover in their Technical Service Bulletins and service campaigns. This listing might be useful in shortcutting the diagnosis process for the most common faults. If your problem does not fit the pattern for those listed here, you should go through a more systematic diagnosis process (watch this space!).

Note: If any of these conditions happens, it is probably advisable to stop the engine ASAP and try to find the cause before the system decides to go into "hard fault" mode. If you can catch and rectify the problem before this, you will probably avoid a trip to the dealer to reset the ECU and get the system running again after the problem is repaired.

Cause 1: Sticking Pressure Switch

Cause 2: Compressor Overheat Signal
If the ECU thinks the compressor is overheating it will freeze height changes and display "Suspension Inactive". It will also store the code storing code 41 "Compressor Temperature Rises when Static". On 2003 and 2004 models up to VIN 4A155162 this can sometimes be overcome by updating the air suspension ECU software. The later software accepts higher readings from the compressor temperature sensor. Otherwise, the problem might be a faulty compressor or temperature sensor, or possibly a leak in the system causing the compressor to be on constantly.

Cause 3: Frozen Pressure Relief Valve
I think this is another possible cause of the "suspension inactive" signal.  If the vehicle is already at standard height on a cold morning, it may be fine for driving but if you try to request a height change it will not respond (and might give the "Air Suspension Inactive" message until the pressure relief valve has thawed out. See "Failure to reach normal ride height" below.

Freezing in High Profile

Cause: Unknown
I suspect the causes may be the same as above, but I am not sure. If you know please email me.

Vehicle Sinks to Bump Stops.

Cause 1: ABS Switch
When the dash lights up like a Christmas tree with warning lights (ABS, EAS etc.) and warning messages ("no dsc no air suspension") on, the EAS can go into hard fault mode, slow to a crawl and settle on the bump stops. It is tempting to think the ECU has failed but that is not usually the case. The most common cause seems to be the input from the ABS system to the EAS ECU telling it to shut down. The problem can be as simple as a faulty brake switch.

Cause 2: Air Leaks
If the vehicle gradually sinks to the bump stops at rest, the most likely cause is an air leak. The early model rear air bellows are prone to leaking in cold weather or if they have been subject to overpressure.

Failure to Reach Normal height

Cause 1: Sticking Pressure Relief Valve
The pressure relief valve will often stick open in temperatures below -20 degrees Celsius, preventing the system from reaching normal ride height or responding to height adjustment commands. Normal operation resumes when the vehicle warms up and thaws the valve. Interestingly, Land Rover's solution for this is not to get a better relief valve design, but to modify the ECU software to work around the problem. The January 2004 service campaign performed this update and installed new rear air springs -- see below. Presumably the software update gets the ECU to ignore the problem til the system has warmed up.

Cause 2: Air Leaks
Especially from rear airbags on models built up to January 2004 -- see below.

Cause: Rear Air Bellows Leaks
Cold weather or overpressure can cause leaks in early build rear air bellows, causing the vehicle to settle to the bump stops when left at rest, inability to rise to normal height, or cause front/rear height imbalances. This problem can be caused by excessive pressure in the system leading to premature failure of the rear air bags. It is not clear why this excess pressure occured, but a service campaign was undertaken in April 2003 on vehicles 3A101029 to 3A106310 to address it by installing a second pressure relief valve (MAV500010K) in the spare tire compartment, in the feed line from the compressor to the air tank. (However, this valve in turn might cause its own problems -- see above). A second service campaign was initiated in January 2004 (for VIN numbers 3A101029 up to 4A156147) to  replace the rear air springs with an improved design and also update the ECU software to get around the sticking pressure relief valve problem mentioned above.

In spite of these fixes, the rear spring bellows still seem to be more prone to leaking than the front. In May 2006 my May 2004 build RR III would sag in the rear after being parked overnight; the dealer found both rear bellows were leaking and had to be replaced.

Please email me if you can shed any more light on these or other air suspension problems.

Page last updated May 2006