shred101

I'm having problems with the Airmatic suspension on my 2007 GL450. The initial problem was that both front struts were completely lowered and not rising up, even when I could hear the pump running. I replaced both front air struts and the air suspension solenoid assembly. The front is still not rising, and now the rear struts are sitting low as well and will not rise either. Does the Airmatic suspension need to be calibrated in order for the system to rise again? And is it possible the pump isn't putting any air out even though I can hear it running? Thanks for your assistance with this.

expl0rer

If you're certain you don't have any leaks in the airmatic, your compressor may be done and needs to be replaced. Do you have any codes thrown for the airmatic?

Also check you height level sensors to make sure they are not seized or haven't popped any arms.

shred101

I don't have a scanner that can read the Airmatic codes. So, I'm assuming that the system doesn't need to be calibrated to pressurize?

expl0rer

No calibration is necessary. The compressor, if functioning properly, will build pressure when the car is running. However, it should be noted that when replacing the airbags, you do not completely drop the vehicle on the ground before starting the car to fill the system with air. You should have its wheels touching the ground but still supported by the jack/lift till the compressor fills the system with sufficient pressure to support itself.

shred101

Ok, Thanks so much for your help. I'll check for leaks, then see if the compressor is putting any air pressure out..

eric_in_sd

It can overheat the pump if you task it with both filling the bags and the reservoir. Other than that, if you like living dangerously, it can be fun to drop the truck all the way to the floor and watch the pump lift it.

eric_in_sd

I hope you saved the old air valve block. I bought a Chinesium one and while it looked good, and returned pressure readings to the system, the valves did not function.

My understanding is that if moisture does not get in the system, i.e. the dessicant in the pump does not get overwhelmed, as in endlessly trying to push air into leaky bags, the valve block will last essentially forever. If you look inside the connector holes in the top, you may see corrosion. I sprayed a little silicone in the air fitting holes on the valve block, just in case.

I ended up putting my old valve block back in.

If the system worked sort-of okay before, and you changed the bags and valve block and it now doesn't work at all, you may have installed a crap valve block. It's amazing, but guys will sell these Chinesium parts, knowing full well they don't work, hoping you'll forget to demand a refund.

And no, the system needs no calibration or initialization. Plug it in, turn it on.

The pump tends to fail gradually. The piston wears inside its cylinder. They simply have a finite number of up-down strokes before they become useless. (insert juvenile reference here) Usually the weakening air pump manifests as an Airmatic error on the dash - the pump tries to refill the reservoir while driving, so as to mask the pump noise, and if it takes too long to bring the reservoir pressure up, the system diagnoses a fault and shuts off the pump.

Leaky air bags can cause accelerated wear on the pump, and the pump shoving moisture through the valve block, so it is important to stay on top of air bag health. As soon as you see it sagging at all overnight, change out the bag. Make a habit of occasionally spraying soapy wooder on the bags when the truck is lifted, to look for leaks.

You really can't own an out-of-warranty GL without investing in - at a minimum - the Icarsoft diagnostic tool. You will need an OBD bluetooth to figure out what the CELs are, but you really will want to have something better. The Star/DAS looks to be a pain in the neck, but the Autel does pretty darn good. Icarsoft will tell you what error codes the system is throwing - it can receive the detailed information - while the Autel will send information too. You can actuate individual valves, that sort of thing. I tried to figure out what was wrong with my air system using the icarsoft, but it was too blunt of an instrument. Still, it served me well; I'm not saying it's a bad thing. Bluetooth adapter, $10; Icarsoft, $200; Autel, $800; DAS $mystery

Max Blast

A DAS clone system was about $800 when I bought one a couple of years ago from user @shardul on this board.
the expanded functionality pays for itself in a year, but I am surprised that my generic OBD2 scanner from Amazon has everything but live read outs.

Pmanc

Hello I had a similar situation the problem was my air pump was not strong enough to fully inflate the whole aromatic system when I change the air pump then I was good to go

eric_in_sd

Yeah, I just never could climb the learning curve enough to convince myself I wasn't going to end up with a Windows XP laptop and software that no longer works.

Straight OBD has limited functionality. Standard codes are reported; they have the same meanings across all makes and models, since 1996.

There are Benz-specific functions that can be accessed through the same bus. Icarsoft, and some cheaper Autel models, can query data from the system computers. The more expensive Autel models can send instructions, such as perform tests on Airmatic. $10 lets you read OBD, $200 lets you read Benz-specific data, $800 lets you send instructions to Benz modules. DAS lets you become God for a while.

Autel provides this functionality for a staggering array of automobiles, not just Benz. It is a pity that I have this power and no Lamborghini to use it on.

Torque Pro is supposed to let you read things like transmission temperature, but people have reported it is crazy inaccurate, like it is reading the wrong data stream.