Working on my 2004 W211 wagon with electrical issues, resulting and related to a blown suspension air pump..(the new pump works great but does not respond to commands from the foxwell or low rear end signals)

Great helpful members have shared that there is a suspension control module which may be blown or de-powered. The foxwell scanner does not show this module on the menu or access it. The scanner can go to just about any component and actuate it, the rear washer sprayer, strut solenoid fill and empty valves..and these work in response to commands entered.

The scanner will tell me in one message that it is possible to test the compressor and then when entering the command it cannot communicate. (could simply be a fried wire in the compressor leads..) Relay and fuse are good.

To really test the air pump leads I suppose Id need to run continuity test from the relay activation pins in the circuit panel down to the motor connection socket..

I simply wired the new air pump (Arnott) to a spare battery and aired up the rear shocks with a jumper being careful not to melt down anything and giving it rest breaks to cool off. And the suspension is restored to full ride height plus a bit..The shocks and reservoir and system do not leak. Holds great..

But the scanner tells me it cannot communicate with the SVCM or special vehicle control module which I find for sale, not expensive, but I cant locate a description of the function of this module. I suspect it may be involved with the nav system which I dont have on this car, or something equally unrelated to the suspension system. All I can learn is that the SVCM is different if its on a taxi or police vehicle or...but not what this critter does! And all I know is I cant communicate with this thing! Whatever it is!!

Thanks anyone/everyone.

Mine doesn't have SVCM What's that?

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You should have one tjts1, on your Foxwell menu anyway since its the same as mine.

I dont have the unit available now but its under the Controls menu I think..how does it go? Engine/Trans/Chassis/body/Controls/suspension... One getsunder controls, the units including the three SAM units and various components and then there is a "special vehicle control module" I have this and the readout is cannot communicate with the SVCM..And it reads out this special vehicle... I do find this unit for sale and various details, photos, but nothing describing its function. Just that its different for a taxi or police car or ...So I suspect something Nav related perhaps?

The sub menu items that appear on in the foxwell are all the possible modules that could be installed in your car. Just because it appears on the list doesn't mean your car has it. In manual mode the foxwell doesn't know whats installed in your car. When you click on it the foxwell will try to find the module but it might not exist. In the sub menus you'll also find a tow module (never installed on any US cars) parktronic radar cruise control, massaging seats etc items that weren't typically installed on E320s.

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Yes, Thanks tjts1, gotcha. I also see the tow module and others and just skipped them. This may be the case and I dont have navigation, and I suspect this SVCM is a navigation module and I dont have that..(yes I also see all these heated seats and steering wheel items I dont have.)

Just wish the scanner had capacity to test that suspension control module or scan for error codes related.

All codes now cleared except one, something about the rear SAM cannot communicate with a warning horn. And I think my bad wiper washer is just the unit failure, not a bad SAM. The headlight that was out came back. Gas gauge the same. Both of these listed as symptoms of a messed up SAM.

Im now needing to choose whether I get a Star system diagnosis to check for a bad suspension control module or just replace the module, (this is cheaper) fingers crossed. And I also need to run a continuity check from the power feed pins on the panel to the compressor pump and the plug at the unit. The failure could simply be a bad lead, which with the high power draw and vibration of the pump isnt unlikely. There is even a service bulletin out for this problem, as I say as well as a lawsuit about the pump failures and suspension loss. ( a whole rash of these around 80 to 120K miles in different models. Meltdowns from a stuck relay)