airmatic pump running permanently over 20km/h and stops below this speed
Thread Starter
Newbie
Joined: Sep 2013
Posts: 12
Likes: 0
ML280CDI
airmatic pump running permanently over 20km/h and stops below this speed
Hello,
I had several problems with the airmatic of my W164 (ML280CDI).
Now I have checked that over 20km/h (12,5mph) aprox the airmatic pump starts running and keeps running until vehicle speed drops below 20 km/h exctly.
Is this normal ?
I had several problems with the airmatic of my W164 (ML280CDI).
Now I have checked that over 20km/h (12,5mph) aprox the airmatic pump starts running and keeps running until vehicle speed drops below 20 km/h exctly.
Is this normal ?
Thread Starter
Newbie
Joined: Sep 2013
Posts: 12
Likes: 0
ML280CDI
Hi again....
After broken the plastic case attached to the compressor (where the air line comes out to the valve block), and 2 air struts, I decided to place a led parallel to the compressor power connector, and checked exactly that as soon as the car reaches 44 km/h, the compressor starts running permanently, and only stops when the speed drops below 23 to 24 km/h, so I guess this was the reason of so many failures.
Now the point is what is making the compressor start running every time the car goes over 44 km/h ?
I was thinking about the speed sensors, but the electronic speed control works fine, the ESP works fine, so I don't think is related with that.
Any help is much appreciated.
Tks,
Antonio
After broken the plastic case attached to the compressor (where the air line comes out to the valve block), and 2 air struts, I decided to place a led parallel to the compressor power connector, and checked exactly that as soon as the car reaches 44 km/h, the compressor starts running permanently, and only stops when the speed drops below 23 to 24 km/h, so I guess this was the reason of so many failures.
Now the point is what is making the compressor start running every time the car goes over 44 km/h ?
I was thinking about the speed sensors, but the electronic speed control works fine, the ESP works fine, so I don't think is related with that.
Any help is much appreciated.
Tks,
Antonio
Last edited by ariquelme; Jun 18, 2015 at 10:02 AM.
Junior Member
Joined: Jun 2015
Posts: 46
Likes: 9
2011 GL450
I believe the system is designed to run the compressor when the vehicle is moving over 20km/h. Pretty sure I read that in the system description somewhere. This masks the noise and keeps the central reservoir pressurized. Are you experiencing any faults currently?
Junior Member
Joined: Jun 2015
Posts: 46
Likes: 9
2011 GL450
I need to revise and extend my remarks. The compressor runs IF the central reservoir detects insufficient pressure, and the speeds for compressor operation are 40km/h under acceleration and 20km/h under braking. Seems like there may be a leak somewhere.
Newbie
Joined: Feb 2023
Posts: 2
Likes: 0
ML W164
Hello,
I have exact the same problem with ML W164, the compressor starts at 40km/h and cuts off after slowing down to 20km/h
Also keeps running when the car level is raised to higher positions(offroad pack). No leak detected anywhere. Compressor pumps around 16 bar. Can the problem be airmatic ecu under the driver seat?
Any ideas will be helpful!
I have exact the same problem with ML W164, the compressor starts at 40km/h and cuts off after slowing down to 20km/h
Also keeps running when the car level is raised to higher positions(offroad pack). No leak detected anywhere. Compressor pumps around 16 bar. Can the problem be airmatic ecu under the driver seat?
Any ideas will be helpful!
