When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Members with Xentry/Bi-Directional Scanner and Airmatic Vehicle Request
This is a long one, stick with me please... but I'll keep the request short:
Anyone with Xentry or bi-directional scanner AND a W212 with Airmatic, can you check for me the power consumption of the level control valves as per the picture below. Thanks in advance!
I'm doing some detective work on the '11 E550 with Airmatic, one issue is the rear-end drops overnight... easy enough fix, right? On the '11 E350 wagon, same issue, turned out to be a chaffed air line. So I sprayed down the lines, fittings, valve body and the air springs... nothing, no leaks. Figured its likely the springs, which have a protective boot and wouldn't allow the soapy solution in (I suspect) to actually see or hear a leak.
Ran Airmatic diagnostics in Xentry, why not since i have it ... all tests pass, except "manual" test of measuring ride height and letting car sit overnight (which we know it fails). If test fails, then its checking the lines, fittings, etc. with soapy solution, then replacing the air springs and checking the "system" for moisture (remember this last part).
While playing around with actuations, I found this odd behavior that got me thinking the issue could be a bad valve body. Under the Level Control Valves, you can actuate them individually and see their power consumption... immediately I saw strange behavior in that some valves drew power when NOT actuated, but ALL drew the same power when actuated. The reservoir filling valve was one that actually switched between 0.0000A and 7.84 mA every second while not actuated. (actuated was steady 682.35 mA). All the other valve readings were steady. My first thought is the valve/s are NOT closing all the way due to moisture/corrosion from both a leaking airmatic for unknown period of time and life in the Northeast. If in fact, they weren't closing, then the air might leak back into the compressor (which has is own valve for pressurizing/depressurizing the valve body) or other spring/strut leaking elsewhere.
When performing actuations on other components (airmatic pressure relief, damper valves, etc...), the power consumption was 0.000 A and then XXX A when actuated, as one would expect. I proceeded to disconnect the pressure line from the valve body to the compressor and sure enough, there's a VERY, VERY small leak when the valve body isn't actuated or even disconnected (electrically). So, regardless the valve body is "bad"... but may not be the source of the "leak" causing the rear-end to drop.
Final twist, I ordered a NEW valve body, since why not, and plugging it in I get the same power consumption values as before.... WHAT? Now I haven't hooked it all up and tested to see if it leaks out the pressure line (I suspect not). Final tests I performed, to rule out a bad connection to the valve body or shorted wire (erroneously activating the valve/s or causing a "draw"), I checked the wires back to the airmatic module, no issues. Also checked the resistance of each of the control valves circuits on the valve body, all were 7.2 ohms (new and old).
So here I am... I'm not sure if the reading in Xentry really means anything or something or the module is "bad". Probably making a mountain of out a mole-hill, though secretly its interesting, as no issues beyond the dropping of the rear-end are present and the change of the air springs and valve body I'm sure will fix the initial "issue".
I do not know as I did not design/build the system but 7.84 mA (0.00784 A) is not high enough load to actuate the solenoid valve. It could be a “checking the circuit” load that the computer use for checking that there is no open loop with the valve(s).
Your car is past 10 years old and it is time to replace the air springs and also soon the air struts in front.
One way to see if it is a leak in one air spring is to leave the car in raised position over night. Then observe in the morning if it went down on both sides or just one. If both sides drop all the way you have air coming out from both sides either thru leak in the springs or lines or valves. I understand you replaced the valve block already so valves should be good.
It is not likely to have both air springs leaking at the same time unless you had the problem for some time and then both leak.
If you have one Spring leaking the back of your car will not go down both sides all the way. Leaking side goes clearly down more but should not go all the way but it also can but the non-leaking side does not go down all the way. This is because in raised position one spring will develop enough pressure to carry that side of the car.
I replaced all my air springs and struts when car was just over 10 years old. Rear spring Arnott thru Amazon about $550 Front struts from FPC Euro for about $2400.
I do not know as I did not design/build the system but 7.84 mA (0.00784 A) is not high enough load to actuate the solenoid valve. It could be a “checking the circuit” load that the computer use for checking that there is no open loop with the valve(s).
Your car is past 10 years old and it is time to replace the air springs and also soon the air struts in front.
One way to see if it is a leak in one air spring is to leave the car in raised position over night. Then observe in the morning if it went down on both sides or just one. If both sides drop all the way you have air coming out from both sides either thru leak in the springs or lines or valves. I understand you replaced the valve block already so valves should be good.
It is not likely to have both air springs leaking at the same time unless you had the problem for some time and then both leak.
If you have one Spring leaking the back of your car will not go down both sides all the way. Leaking side goes clearly down more but should not go all the way but it also can but the non-leaking side does not go down all the way. This is because in raised position one spring will develop enough pressure to carry that side of the car.
I replaced all my air springs and struts when car was just over 10 years old. Rear spring Arnott thru Amazon about $550 Front struts from FPC Euro for about $2400.
Job to change is very easy.
This was more a curiosity if the Xentry readings were meaningful... the behavior doesn't indicate error checking to me as its not consistent among the solenoids, nor does it exhibit on another airmatic (EHNR) car.
The E550 is new to me and indications of a leak were present at purchase
both sides drop overnight
no leaks in air lines
valve body has very slight leak out compressor port
I'm going to replace the valve body and rear air springs anyway.
This was more a curiosity if the Xentry readings were meaningful... the behavior doesn't indicate error checking to me as its not consistent among the solenoids, nor does it exhibit on another airmatic (EHNR) car.
The E550 is new to me and indications of a leak were present at purchase
both sides drop overnight
no leaks in air lines
valve body has very slight leak out compressor port
I'm going to replace the valve body and rear air springs anyway.
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren
Slideshow: A one-of-one U.S.-spec Mercedes-Benz SLR McLaren Roadster became even rarer after a factory-backed transformation at McLaren's headquarters.
... all tests pass, except "manual" test of measuring ride height and letting car sit overnight (which we know it fails). If test fails, then its checking the lines, fittings, etc. with soapy solution, then replacing the air springs and checking the "system" for moisture (remember this last part).
