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Lou P. master tech
Lou P. master tech, Mercedes Technician
Category: Mercedes
Satisfied Customers: 4955
Experience:  15 years master certified 100% fix rate and have access to factory radio codes, wiring, and instructions.
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I have a 2007 gl450 that has had many suspension issues.

Customer Question

I have a 2007 gl450 that has had many suspension issues. I've replaced the front struts and rear air bags. I recently had to replace the ride height sensor on the rear passenger side, but now the suspension won't respond. I've also replaced the compressor about 6 months ago. I had a mobile MB mechanic take a look at it, and he got the system to respond and even raised it. I tool it to the dealer and they charged me $300 and all they told me was that I should replace the sensor with a factory sensor which would lost me another $400. I bought another sensor online and installed it myself but still can't get the suspension to respond. I've searched on how to reset the system but can't find anything other than to disconnect the power terminal. Cam you help me figure this out
JA: How has the ride been lately? Have you noticed any fluid under the car?
Customer: The rear us low and has been bouncing and bottoming out. No fluid leaks
JA: What is the model of your '07 Mercedes?
Customer: 2007 GL 450
JA: Are you fixing your GL yourself? What have you tried so far?
Customer: Replaced the compressor. Replaced the fuses and relay. Replaced the ride height sensor twice
JA: Anything else you want the mechanic to know before I connect you?
Customer: I replaced the rear sensor because the arm broke and that's when my problems started
Submitted: 2 months ago.
Category: Mercedes
Expert:  Lou P. master tech replied 2 months ago.

Hello, my name is***** and i will do my best to assist you.I am going over your story now and will reply back soon with some info,thanks!

Expert:  Lou P. master tech replied 2 months ago.

what do you mean by you cant get the suspension to respond?

Expert:  Lou P. master tech replied 2 months ago.

the sensors never are at fault, usually its the plastic arms on the sensor brackets, they corrode to the socket joint and cause leveling issues, can you verify if yours move freely?

Customer: replied 2 months ago.
It says malfunction on the dash and it simply won't work. It will not go up or down. I checked for power on the fuses but there isnt anything at all. The arm on the sensor is moving freely as well.
Expert:  Lou P. master tech replied 2 months ago.

ahh ok, if the malfunction comes on right away then there is a signal malfunction and the control module is locking out compressor function,

can you tell me if you were ever given any fault codes? from the dealer or the mobile tech?

where are you located?

Customer: replied 2 months ago.
The dealer said the sensor is shooting different numbers. So I bought a new one and installed it today, but it's still not working
Expert:  Lou P. master tech replied 2 months ago.

ok, a code would be nice, hmmm

I can definitely help with this. but it would be nice to have a scan tool that can read the values, I do not suggest replacing any parts until we can get some live data to look at , what are your options?

Customer: replied 2 months ago.
I've hit a dead end. I don't know what else to do. What do you suggest?
Expert:  Lou P. master tech replied 2 months ago.

can you take a few pictures of the rear left and right sensors and send them to me?

i want to see if they are installed correctly,

well on 1-10 what is your mechanical ability?

Expert:  Lou P. master tech replied 2 months ago.

there is a decently prices scan tool on ebay that i recommend to mercedes owners that like doing work on their own,

icarsoft mercedes,

check that out on ebay, can save you hundreds in the long run if not thousands.


Customer: replied 2 months ago.
On a scale of 1-10 maybe 6-7
Customer: replied 2 months ago.
Sent pics of the sensors
Expert:  Lou P. master tech replied 2 months ago.

ok is the car up in the air right now or on the ground and yes i see them thanks for that

Customer: replied 2 months ago.
I left it up
Expert:  Lou P. master tech replied 2 months ago.

ok, if the car is on jack stands or the doors or hood are opened the compressor will not come on and function fyi,

the rear sensors look good for installation, one thing i see that i dont like is in the second picture you can see a wiring loom in the background that is at a rough 90 degree angle, a lot of the wiring in the back underneath had a protective sleeve that would actually trap water and wear wiring if cocked like that, so it may be best to make sure that loom is not for the sensors.

Expert:  Lou P. master tech replied 2 months ago.

here i circled the wiring i am talking about, looks like the right side.

Customer: replied 2 months ago.
Ok I straightened out the wires
Expert:  Lou P. master tech replied 2 months ago.

ok lol, maybe i should have specified, we need to see if that harness does go to the sensor and also try and gently cut back the covering to expose the wires to make sure no wires are broken inside.

its a long shot but it all depends on if that harness goes to the sensors.

I have to go for a bit , I will be back online later.

at this point I know we didnt make much progress, what we really need is a scan tool to get fault codes.

that is where we need to start based on your scenario, so let me know what you want to do from here and i will gladly assist.

I have taken my time to answer your question the best I could and I will continue to help if you need follow up information , all I ask is that you PLEASE take a second to rate my service so I may receive my credit for assisting you, Thank you.
Lou Palomino
Master Mercedes-Benz Tech
Master ASE Certified Tech

Customer: replied 2 months ago.
It was part of the wiring harness to the sensor. I checked both sides and made sure the wires weren't damaged
Customer: replied 2 months ago.
I'll get the scan tool and hit you up when get it
Expert:  Lou P. master tech replied 2 months ago.