2014CL600

I just measured my cars ride height because the front was looking low on the passenger side. Sure enough it was low but then I noticed the RH rear was also low. I started the car and used the button to raise and lowered the car. I let it run for about 5 minutes, since I haven't driven the car in about 2 weeks. I decided to leave it in the raise mode and left it for a few hours. When I came back the ride height hadn't changed but I did notice no matter whether in raised mode or normal mode, the LH rear did not go up or down, it stays at 27 1/2". The other wheels were at 30" in raised mode. I have NO warnings on the dash but I'm thinking that my ride height sensor is bad on the RH rear wheel. The car only has 10K miles and I'm wondering, if the sensor was defective wouldn't the dash light come on? Believe it or not the last owner was convinced by the dealership to replace the two front struts because it was listing to one side. They also changed the height sensor as well. I know, he probably only needed the sensor. Shouldn't I have a warning on my dash if the sensor was not working? Any thoughts? was thinking of buying a new sensor and just changing it out. If I could find the arm at the strut I would move it up or down to see if I got any reaction. If it doesn't change the height, for 56.00 I'd just buy an OEM Mercedes sensor and change it.

BenzNinja

iTrader: (4)

easy way to find out is hook it up to Xentry
you will know within 10 min if something is wrong

2014CL600

I have no idea what that is. If I need a diagnostic tool, I'll just have to take it to a dealer. I'm just asking, can the sensor be bad and it not show up on the dash, that's all.

BenzNinja

iTrader: (4)

a MB diagnostics system
your car is a big computer, something you can't really repair much without diagnostics

BOTUS

if it has std airmatic, they have 3 sensors
one each on the front and one at the rear
all three seize and snap off its normal, the rear is a nasty job to reach, the front sensors are a 15 minute job
the pumps wear out and fail its normal,
all 4 struts will fail its normal, anywhere from 10 years 50 k miles, might get 14 years and 200k miles its a lottery...
saggy left rear can be a fault from new with a scored pipe that leaks
you can get the pump stop with a blown fuse and no warning lights, the system falls back to a not running lock in air and if the height is OK it can be like that for a year, a few more months of leaks and a few big loads can trip till it says go get it fixed - check F56 an orange 40 amp fuse under the bonnet (driver side SAM)
there's a test to see if the pump is OK and if the system is leaking its takes 10 mins

if you have the option ABC they are better but without a bi annual service and fluid change it will make the airmatic system look cheap to run

2014CL600

Thanks but I have NO leaking and or pump problems. The electronics seems to be the issue. If I raise the car to its highest level and lock the car, it stays in that position, without leaking down. If I put it in the normal position, I can hear some odd clicking from in the engine bay at the RF wheel area, once I lock the doors. It makes a high frequency noise, releases air, then repeats one more time until it settles at the 28" vers the rest of the other fender heights at 29". After about 20 minutes the same side rear lowers to match the RH front. I'm thinking the sensor is possible defective. They struts were replaced at the dealer about 5K miles ago and so were the sensors.

BOTUS

oh - well go back and ask them to look at it

for everyone else - take a read of this post last week - the sensors link rods should be seen as a service item. lube every year, replace every 7, you have three sensors, (2 x front, 1 x rear)

https://mbworld.org/forums/s-class-w...ic-2007-a.html

DaleB

For Airmatic, yes. For ABC equipped cars, four. One on each corner.

EasyPhil

Also don't forget to change the air filter attached to the compressor.

2014CL600

I decided to go back, wait the 30 seconds and let the car level out. I didn’t lock the door and the car is still sitting at 29” at all four corners, 4 hours later. If I lock the doors, the car will drop. It’s totally electrical in nature. Would it be the block or the front sensor?

BOTUS

sounds like an air leak,

with the key out (locked or unlocked) the level shouldn't change, over a few days of non use with big changes in atmospheric conditions they breath up to 1/2" (up or down) but if the atmospheric pressure is stable and its not driven it should sit without any change in ride height at all and the pump shouldn't need to sort anything before driving away..

2014CL600

If it had a leak, the car would drop down. I am now 28 hours out from starting the car and it still not lowered at all. So, that being said, it is electrical. I haven't locked the door but I'm sure when I do, the car will settle down on the passenger side, (front and then work to the passenger side rear). I know it's only and inch but it looks horrible. I was asking, does the valve body block control the electronics part of the system, or is that done with the level sensor only?

BOTUS

on many Mercs (though not heard anyone say on in a 221) a failed airbag can seal itself when parked, so it can sit and not go down but in use the pump is fighting to keep up a sinking ship.

if something amiss we can't fix it here?

2014CL600

Thanks, I think I'll just take it to the dealer and have them adjust the ride height. Seems I'm not getting anywhere here.

DaleB

Sounds like a good plan.

EasyPhil

Don't be surprised if you don't get anywhere at the dealer either.

doni01

iTrader: (1)

Unfortunately very true!

BOTUS

if its airmatic then side to side is controlled ONLY from the front, one sensor (at the back) does up down ride height at the rear,

often an airbag will leak down and seal itself and not collapse down to the floor... the pump will them bring it back up, but wear its self out doing so.... Mercedes invented plenty of tests to see what's happening using their dealer equipment, we can only offer ideas....

Arrie

So, if it is the right front that drops then that level sensor is what I would look at. I have an iCarsoft MB II scanner that shows all level sensor readings. If your right front drops lover than left side then the sensor could be reading wrong, i.e. it is bringing the car to the correct height based on the sensors and if the right front sensor reads wrong then it will go to wrong level.

Rear coming down with is because the car body is stiff so if you make right front go down it will also push rear right down some with it and makes left rear come up some. If rear left comes up enough to move the sensor up then the car will lower the rear down to the correct level sensor reading.

Perhaps this is level calibration issue or you just need a new sensor for the right front.

2014CL600

Yes, that is my thinking. The sensor is either out of alignment or it's signal is off. It isn't the strut and there is NO leaking and the pump NEVER just runs, except when I start the car and only for about 15 seconds). Like I said, it only drops after I lock the doors but not until then. I actually left it for a week and it was still at 29", all the way around. The second I locked the doors it immediately dropped 1/2'', then 15 seconds later, drops the other 1/2". It's an easy and cheap try. If it doesn't work then the dealer can have a crack at it.

BOTUS

had mine 6 years it has never done that ever.
on some JLR with air suspension it has a drop mode to allow access and egress.
the pump that runs unlocking the car is in the boot left hand side and is for the seats.

once an animatic pump has settled in it runs almost imperceivably... the OEM replacement was very loud (its under the right hand headlamp) but after 6 months now almost silent. If you have the car idling and press the raise button on the dash, the engine noise is more than the pump

2014CL600

....

2014CL600

I raised the car to the full 30" height and locked the door. The car doesn't drop at all, It has stayed up for over a week now. The only time it drops is when the car is in the normal height position and the door is locked. I am thinking the height sensor is defective. It is the only possible thing logically that it could be. If the NEW struts were leaking or the valve block was leaking, it would drop no matter what height position the car was in. I'm guessing the sensor is sending the wrong signal at the normal height position.

seiltaenzerin

Hi 2014CL600,

I have also experienced this issue where the front passenger side air strut settles after locking the vehicle. And just as you have found, it only happened when the car was in the normal driving position—and it did not settle the front right strut when I engaged the raised driving position.

Oddly enough, if I left the car to sit, the front driver side would settle too. I understood this as the vehicle attempting to self-level right-to-left, so everything remains in parallel.

The issue was not due to a leak in the AIRmatic system. I tried finding others who experienced a similar problem. An individual explained that there was be low voltage at the electrical connector for the level sensor in the wheel well (caused by moisture and debris finding its way into the connector). While this remedied their issue with the vehicle settling, my electrical connector appeared in-tact, and the voltage read normal in DAS.

Anyway, I gave up finding a solution for this and decided to leave the car raised every time it parked for months and months until recently when I inadvertently discovered the cause of the settling. I got around to replacing a faulty rear parking sensor, so I finally decided to plug in the electrical connector for the rear parking sensor wiring harness. After reconnecting the parking sensors, the vehicle has been left in the normal driving position—locked—and has not settled as it did previously. I initially imagined a bad valve block solenoid or a lousy strut, but somehow it was related to an open circuit from an unplugged wiring harness in my case.

I know this may not be the most helpful information, but I am trying to explain that it may not always be a leaking air strut or bad valve block solenoid. It could be something completely unexpected like an open circuit or parasitic draw that messes up the finicky computer modules in the car. I think you are headed in the right direction with your diagnosis that it's electrical-related, though.

Please let me know if you would like me to elaborate more on my issue. I hope this helps, and best of luck finding a solution!

Best regards,
Christopher

BOTUS

Whilst this shouldn't happen, the fact it does on this model doesn't surprise me....

would be interesting to see if any software updates where applied to the vehicle during its life... the ones it left the building with, with the exception of the engine, the box, the doors and the comand seem to have been less full of errors than the replacement stuff