Strange Airmatic behaviour - car rises at redlights/stops.
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2 cars from Bavaria
Strange Airmatic behaviour - car rises at redlights/stops.
As described, the car (a 2001 S430 4matic) has started to slowly rise, when running, but stopped at a red light or stop sign or in traffic.
No previous Airmatic problems up to this point.
Anyone had this happen? Probably won't DIY fix it, but just wondering what the likely repair solution/bill might be.
Thanks!
No previous Airmatic problems up to this point.
Anyone had this happen? Probably won't DIY fix it, but just wondering what the likely repair solution/bill might be.
Thanks!
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Mercedes
My car does this too., the car lowers at freeway speeds and rises when you come to a stop, do you notice this coming off a freeway offramp to a stop sign?
if so, that is normal.
If it is happening at slow speeds in town, you may have a leak, spray some soapy water on the strut tops inside the engine compartment and check for bubbles
if so, that is normal.
If it is happening at slow speeds in town, you may have a leak, spray some soapy water on the strut tops inside the engine compartment and check for bubbles
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From: Tampa, FL
2005 S500 4-Matic, 1978 450SL
Tusabes, do you keep your car in the "raised" position? That's the only time what you describe should occur.
Driving the car raised decreases its stability; it is supposed to be used if you're encountering particularly rough roads, or using chains.
Driving the car raised decreases its stability; it is supposed to be used if you're encountering particularly rough roads, or using chains.
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Cayenne GTS, Cayenne Turbo
There is hysteresis with the raising/lowering.
Starting from the normal height setting:
1) From 0 km/h, the car lowers automatically at v >110 km/h to -5mm
2) From 110km/h, the car raises automatically at v <60 km/h back to normal height
Starting from "Raised Level" (+30mm) setting:
1) Raised level is canceled after 5 mins if v > 80 km/h
2) Raised level is canceled immediately if v > 120 km/h and lowered automatically to -5mm
One *may* notice the 5mm raising from the normal height setting if the car decelerates from >110 km/h to <60 km/h immediately. Additionally, the valves are not lowered at the same time; the rears may release pressure first THEN the fronts, hence the delta of 5mm *may* seem more.
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From: Tampa, FL
2005 S500 4-Matic, 1978 450SL
Arnee,
What type of hysteresis is creating the lowering? What part of the system does it occur in? Are the ride height sensors set to create this?
What type of hysteresis is creating the lowering? What part of the system does it occur in? Are the ride height sensors set to create this?
Last edited by Skylaw; Apr 23, 2010 at 05:10 PM.
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Cayenne GTS, Cayenne Turbo
It's programmed that way. The airmatic module gets input from the steering wheel sensor, speed sensor, etc.
The height sensors are just there to provide feedback to the module.
Per the WIS, this is how it's done. I wish I could post all the pages from the WIS. There's a lot of info from it on the airmatic function.
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From: Tampa, FL
2005 S500 4-Matic, 1978 450SL
So then it is specific programming of the module that causes the raising and lowering - thanks. I was aware of the second half of your initial post - lowering the car if it was raised, above a certain speed for a certain time; and then raising it again at lower speeds. The amount of rise with the dash switch is 3/4 inch.
I learned something with the other information you provided. Very interesting. At 5 mm rise/lowering, that's just under 1/4 inch, and it could be visible to the driver.
I learned something with the other information you provided. Very interesting. At 5 mm rise/lowering, that's just under 1/4 inch, and it could be visible to the driver.
Last edited by Skylaw; Apr 24, 2010 at 09:49 AM.
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