cswackha

I have a 2007 GL450 and the "Suspension Malfunction" error message appears in the information window. The suspension is not sagging or bleeding off. It seems to function fine except I cannot change the suspension settings (sport vs. normal vs. comfort). When the car is first started, it is fine, but after a few minutes of driving the error message will display and the suspension setting is stuck in sport mode.

Is this related to some valve sensor or possibly the ride leveling system? Thank you for helping.

Max Blast

if you have a sport/comfort button you have ADS.
is the error related to trying to select sport/comfort or raising the car?

the latter is usually caused by a burned out compressor. If you’ve made recent changes to your air suspension springs or hit some road debris it is possible that it could be a missing, disconnected or bent level sensor.

if it happens only when selecting sport/comfort your issue is with the ads solenoid on one or more shock dampers, it’s wiring harness, the ecu or the button itself. Maybe there’s a half caf latte coating the buttons innards and it is sticking?

there’s a wealth of airmatic and ADS failure mode information on this particular sub forum, if you search you may find a symptom case like yours with the appropriate resolution.

if it is ADS there should be trouble codes - have the car read out with an mB scanner and report back.

Pmanc

Chances are it may be the air compressor is not strong enough to keep filling up the suspension

cswackha

Thank You Max Blast. The suspension malfunction error only occurs after about 2-3 minutes of driving. While sitting in the driveway idling there are no issues. Before the error occurs, you are able to change the suspension mode without issue. The suspension does not sag or lose pressure. I am also able to increase the ride height without any issues. Is there a cheap code reader I can buy that will display the ADS issue? I have an OB2 reader but it does not do ADS.

eric_in_sd

The basic suspension error message means that the pump is taking too long to fill the reservoir. This is the early warning sign that the pump is dying. You can make some adjustments because the system is using the remaining air in the reservoir. The system waits until you are driving to refill the reservoir. That is why you can adjust ride height in the driveway but then get an error message later.

Stop fiddling with it and change the pump. Otherwise you will find yourself with a lowered suspension and no pump to lift it. Then you'll get the nasty error message because you really shouldn't be driving with the suspension bottomed out.

The consensus is you have to get an AMK A1991 pump, sold under the AMK name or with other stickers, such as Bilstein, on it or you will only get about 20k miles out of it.

Get an icarsoft MBII and you can read the Benz-specific errors. Pay four times as much and you can fiddle with the systems directly.

cswackha

Thank you, Eric. I already have another air compressor so I will NOT diddle around any longer. I will replace it.

eric_in_sd

Good for you - that's the AMK pump with an Arnott label on it. Should last you a nice long time.