Profile picture for user K2
K2
Question Details

ok so i have tried to take this on and I'm now stumped , usually I'm pretty good at diagnosing a problem.. so car has not been ran in two years and car is literally on its belly can't move it without damaging fender , fired car up and got the infamous stop car to low message, pump was not coming on ..so ok i found the fuse ..good (15amp inside next to steering wheel, aromatic buttons light up etc...

so then i found the relay and relay fuse both good... jumped the relay pole to pole, pump fires up and runs but won't raise car ..hmmm

so then i start the car jumped relay still no raising of car..

took apart valve body excellent shape no corrosion etc.. jumped solenoid on valve body. works

tried solenoid on pump that one works to..

just for fun i loosened up hose connection on top of front strut got pressure up there...

What the F is going on, im suspecting the control computer under passenger kick panel but i have a hard time believing this went bad? is there a valve in the strut that is activated by the computer to let air into it? it s the only thing i can think of why it won't fill the shocks up with air , all 4 will not raise at all, i could see one or two maybe not rasing but all 4 i would have to think this is electrical of some sort but all power relay and fuses are good?!!

anything else i can try to just get the car up ?

 

 

Comments

Profile picture for user MercedesMedic

MercedesMedic  5 months ago

Do you have star diagnositics or any sort of professional scanner? 


Profile picture for user K2

K2  5 months ago

I've got a bosch scanner but it won't scan the airmatic system, im racking my brain on this and can't figure out anything it could be, I've got it on my lift and the level sensor work because when i raise the car with the lift the red message saying to low to drive goes away, could one sensor shut down the whole system?

 


Profile picture for user MBFanatic

MBFanatic  5 months ago

You need to run a few airmatic tests with a scanner that does bi directional function. 

It is not one sensor shutting down the whole airmatic. 

You most likely have an Air Suspension compressor that is not generating the required pressure or a large leak to the air reservoir. 


Profile picture for user K2

K2  5 months ago

no hissing air from any components, however i did check the tank in the trunk and it had very little air in it , what im confused about is why wouldn't  there be any voltage at the plug to turn on the pump? if the pump is not even coming on to generate a low signal to the computer?

seem i would get the pump to come on before it would generate a fault of low pressure etc.

i did check the pump when it was out and i put my finger over the hole for and it  was hard to keep my finger on it  

what would be a cheap option for a scanner to diagnose this issue?  the icarsoft 980?


Profile picture for user K2

K2  5 months ago

ok i just took off the air tank line and hooked up my shop air directly to the line and there is no leaking anywhere it holds pressure when i unplug it , so there is no leaking..i started the car and the computer should have let the pressure from the shop air into the shocks?>? im at 140 psi which should be enough    nothing happened still on its belly 


Profile picture for user MercedesMedic

MercedesMedic  5 months ago

What do you mean by the pump in the trun? The air compressor is at the front of the car. Passenger side behind the front bumper. 

Depending on the code, the car may not raise even if you provide the required psi. I would not connect a air pressure line directly to the system. You don't want to blow off any air lines or air struts. 

Icarsoft mb ii can  read air suspention codes but it can not do any tests of the air suspention components. 

Autel DS708 for example can read, clear the codes and also perform air suspention tests. 

At this point I would at least find a way to read the airmatic codes. Address any issues or codes. Then clear the codes. 


Profile picture for user K2

K2  5 months ago

i hooked up the air to the air storage tank in the trunk  i believe this would be the expansion tank that the compressor fills for on demand air pressure   I had 140psi to the line from tank and nothing happened, going to order the new piston ring and i have a computer coming for the suspension 

still baffled at why it won't try to turn on compressor to even see if it can produce enough pressure?

ordered the icarsoft mbII for the bi directional functions for the air matic said it would do it hope there right?

 

 


Profile picture for user MBFanatic

MBFanatic  5 months ago

There may be stored fault codes in air suspension module that will prevent the system from running. Sometimes if the car is too low the system will not engage.

I know icarsoft will be able to read and clear codes but not sure what tests it can do. 

Here are some tests you might want to perform 

Air suspension compressor test

air suspension to air tank leak

valve block test

Also read the fault codes and address any coats that have present status delete the rest of the codes that show as stored. 


Profile picture for user MBFanatic

MBFanatic  5 months ago

Any new updates on this issue? 


Profile picture for user K2

K2  5 months ago

I’ve got a Autel maxisys elite coming Tomm so after o hook that up I will know what is going on hopefully.  I also ordered the pump piston ring rebuild kit to make shure my pump is strong.  Thanks for keepUng in touch. I’ll post a update Tomm afternoon 


Profile picture for user BMWadict

BMWadict  5 months ago

I had a similar problem on my W220 and it would not raise once the car was dropped to the min.


Profile picture for user K2

K2  5 months ago

I have the car on my lift and i can raise it off the ground until the red message on dash goes away, but it still won't engage the system, i will be resetting the codes later today and i got another suspension computer to swap into the car hoping that it won't have any stored codes, this car sat for 2 years with 2 dead batteries so i have a hard time believing that it has stored codes still...but maybe 

 


Profile picture for user K2

K2  4 months 4 weeks ago

So update, i got my maxi sys and jumped right into the module and found a lot of stored codes, cleared them and jackpot..got the compressor to turn on and raise the system, however i have a rear axle level sensor that is way out of wack and not responding to level or any tests, so my question is... HOW the hell do you get that thing out?? it looks to be in no mans land between the drive shaft and exhaust tucked up to where my girl friends hands couldn't get up there... is there a good diy video or tricks on this removal?

 


Profile picture for user MBFanatic

MBFanatic  4 months 3 weeks ago

I know it is hard to get to but it can be done.

This may help a little

Let us know how it goes for you.

You may want to consider taking a few pictures and share your thoughts by posting a DIY guide