Airmatic problems - circuit 30G. E350 CDI '11
! Today I got a message in the display "fault" followed by a symbol showing "raising". I have just checked the car for faults and the following faults are registered in the "airmatic module" - see inserted screen shots. The car drives fine, stands at the same level in all four corners, but cannot be "raised" - what does a wise man do ?




So it is not always HOT like Circuit 30, which is forever having +12V from battery until we disconnect it.
So it seems most of the airmatic components get power from the Circuit 30G, and loosing power will give you those whacky DTCs in such high numbers which their explanation sometimes does not make sense.
I don't have airmatic so I am not familiar with their actual wiring, but I know how MB wire components.
Now, F32 Prefuse box has a few outputs, some are Circuit 30 and some are Circuit 30G.
Below is for my car, a B03 start stop version, 2 wheel drive RWD only and no airmatic.
So from this F32 Prefuse box, it then send Circuit 30 power to Front SAM fuse box and Rear SAM fuse box.
It also send Circuit 30G to both Front SAM and Rear SAM fuse boxes.
This is the F32 prefuse box
Now, you find where the airmatic system get its Circuit 30G power ? Front SAM or Rear SAM ?
When found, use your Xentry WIS feature to find the wiring diagram and find the real Fuse or Fuses supplying power for the airmatic system. Will be a few fuses for sure.
The Xentry has a direct link to EPC/WIS information under TEST menu of the module you are looking at, in this case your Airmatic system.
Also could be that the airmatic is not only using Circuit 30G, but a more downstream one where there is another relay involved. If so, look for the relay.
The WIS wiring diagram and function diagram will tell you all these.
Have fun and some migraine

So it is not always HOT like Circuit 30, which is forever having +12V from battery until we disconnect it.
So it seems most of the airmatic components get power from the Circuit 30G, and loosing power will give you those whacky DTCs in such high numbers which their explanation sometimes does not make sense.
I don't have airmatic so I am not familiar with their actual wiring, but I know how MB wire components.
Now, F32 Prefuse box has a few outputs, some are Circuit 30 and some are Circuit 30G.
Below is for my car, a B03 start stop version, 2 wheel drive RWD only and no airmatic.
So from this F32 Prefuse box, it then send Circuit 30 power to Front SAM fuse box and Rear SAM fuse box.
It also send Circuit 30G to both Front SAM and Rear SAM fuse boxes.
This is the F32 prefuse box
Now, you find where the airmatic system get its Circuit 30G power ? Front SAM or Rear SAM ?
When found, use your Xentry WIS feature to find the wiring diagram and find the real Fuse or Fuses supplying power for the airmatic system. Will be a few fuses for sure.
The Xentry has a direct link to EPC/WIS information under TEST menu of the module you are looking at, in this case your Airmatic system.
Also could be that the airmatic is not only using Circuit 30G, but a more downstream one where there is another relay involved. If so, look for the relay.
The WIS wiring diagram and function diagram will tell you all these.
Have fun and some migraine





Based on a quick look, there are two fuses. But the N15/3 Airmatic controller itself is using Fuse F68 from Rear SAM.
The compressor is using stand alone BIG fuse, which is at F32 prefuse box.
Assuming I am using the correct diagram for ur particular car. I dont know your VIN, so cant check data card, so I cant tell with 100% certainty.
Based on a quick look, there are two fuses. But the N15/3 Airmatic controller itself is using Fuse F68 from Rear SAM.
The compressor is using stand alone BIG fuse, which is at F32 prefuse box.
Assuming I am using the correct diagram for ur particular car. I dont know your VIN, so cant check data card, so I cant tell with 100% certainty.
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Attached lots of migraine boost for you

01. First check the fuse Fuse F68 at Rear SAM. Is it blown or not ? Use multimeter to confirm and use a small load like a test light at both side of the fuse.
One side of fuse is incoming power, one side is output power.
02. Let me know those DTC you got, which module is/are the reporting module/s ? Also which one are STORED and which one is a CURRENT DTC ?
If Airmatic module N51/3 loss power and is still without power , its designated buddy modules will be the one doing the DTC reporting.
So show them all.........
Last edited by S-Prihadi; Aug 31, 2023 at 06:16 AM.
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Near N30/4 ABS pump assy means it is at engine bay....

The true location is inside the cabin......LOL


