Bryan Herrin

2012 GL450 with 190k miles

Problem started one day after raising the suspension to the off-road level, just for fun. Didn’t notice anything out of the ordinary straight away, but within a few days the suspension became bouncy.

Over the next couple weeks, the Airmatic Malfunction light came on more and more often until finally it comes on every time I drive now.

The GL isn’t bottomed our, yet and I haven’t known the compressor to initiate since having this problem.

It’s now extremely bouncy but level and low.

I’be looked at all 3 fuses, replaced the replay and replaced the compressor. Compressor still does not pump.

Please help, wife is loosing patient with to have her vehicle back. Have ordered a new valve block, But not convinced that will solve the problem.

Bryan Herrin

Just verified again that compressor will run with 12vdc supplies.

carlosrg

so you need a tool to check to see if any there are any codes in the airmatic system.. iCarSoft can tell. In iCarSoft it will tell you height of all the four wheels and voltage. But most likely your bag pressures are too high and that could be caused by things like. Height sensors, and block valve.

Bryan Herrin

Diagnostic tool would be great, but don’t currently have one. It has slowly dropped in ride height, just not bottomed out yet, so I doubt bag pressure is too high. I’ve got a valve block coming tomorrow, hopefully that will tell me something; maybe just not distributing ANY air.

B-tsai

If its leaking air from multiple corners when parked as well, I'd bet it's the valve block.

Max Blast

If it’s been leaking for a while your compressor is burned out - it might run on 12v but who knows what it’s putting out. Check your height sensors with a live scan tool.

Miguk_Saram

If you can raise the vehicle by pressing the [Raise] button, then the compressor is likely still functional.

If the vehicle does not raise, then check for audible/tactile clues that the compressor has engaged after pressing the button. In the absence of audible/tactile clues, pull out your trusty multi-meter and check your supply voltage to the compressor. If you have proper voltage (but the compressor does not engage), then the compressor is malfunctioning; otherwise, you have a circuit problem - double check your fuses and test for voltage at each fuse (after pressing the [raise] button).

Also, if the compressor does engage, check the compressor air outlet to ensure it is, in fact, pumping air.

gl450x164

Replace the f4kn relay in the rear right side compartment

Bryan Herrin

Ok, so here is what I’ve done, which has gotten me nowhere:

• verified compressor runs off vehicle
• verified compressor is getting no voltage on vehicle
• replaced valve block
• replaced Airmatic relay under hood
• Replaced f4kn in trunk
• check all other fuses related to Airmatic

The compressor just doesn’t activate. Took about 4 weeks for air shocks to lower ( don’t think they have dramatic leak). I get the Airmatic ‘Malfunction’ Icon on dash, and sometimes the ‘compressor cooling down’ message. But compressor doesn’t pump at all.

What’s next?

gl450x164

Have you checked the height adjusters to make sure they arent bent and can freely move?

Max Blast

So - it would seem the compressor burned out a while back and any voltage or current supplied to it by the car’s harness is only serving to burn out wiring and relays.

sounds like you needed a new compressor a while back and a thorough wire tracing job now, unless the culprit is a stuck or binding level sensor.

gl450x164

Ive been down a similar boat trying to figure out airmatic problems...investing in star/das is greatly valuable here as a lot of relay/systems can be tested with it

rhayder

My front height adjusters have a slight bend in them on an X166 I think they come this way.