Does your airmatic compresser start every time you unlock the car?
Thread Starter
Junior Member
Joined: Dec 2003
Posts: 64
Likes: 0
From: Hallandale Beach, FL
C32 AMG
Does your airmatic compresser start every time you unlock the car?
Does your airmatic compresser start every time you unlock the car?
Mine does.
Sometimes I get a red screen that says reducing braking effect. I never hear anyone talking about it, so I am curious.
Thanks
Mine does.
Sometimes I get a red screen that says reducing braking effect. I never hear anyone talking about it, so I am curious.
Thanks
Senior Member
Joined: Oct 2004
Posts: 271
Likes: 1
From: Hertfordshire, UK
ML 320 CDI
I would think the noise you hear is the SBC system charging itself, not the airmatic.
If you are getting a red message saying reduced braking then something is wrong with the SBC system, get it to the dealers ASAP
If you are getting a red message saying reduced braking then something is wrong with the SBC system, get it to the dealers ASAP
Senior Member
Joined: Jul 2004
Posts: 274
Likes: 0
From: Southern California
'03 E500
Interesting...
when I lock or unlock my car..i hear 2 noises..a pshhhhhhhhhh..and a grrrrrrrrrrrrr... I thought it was the sound of my airmatic thing kickin in and then the car adjusting the ride height prior to rolling out.
when I lock or unlock my car..i hear 2 noises..a pshhhhhhhhhh..and a grrrrrrrrrrrrr... I thought it was the sound of my airmatic thing kickin in and then the car adjusting the ride height prior to rolling out.
MBWorld Fanatic!
Joined: Mar 2004
Posts: 5,017
Likes: 16
From: Ft. Lauderdale Area, USA
2015 ML 350
Very good description of the sounds. I noticed the other day that as soon as I unlocked the doors & started to get in the first thing in the morning, the car let the air out of the airmatic and the car lowered itself (Pssssssss...). As I stepped on the brake pedal to start the car (keyless go) I heard the GRRRrrr of the SBC pump. So there you go.
Trending Topics
Super Member
Joined: May 2004
Posts: 755
Likes: 2
From: USA
LS7 powered Corvette
Originally Posted by Barry45RPM
Very good description of the sounds. I noticed the other day that as soon as I unlocked the doors & started to get in the first thing in the morning, the car let the air out of the airmatic and the car lowered itself (Pssssssss...). As I stepped on the brake pedal to start the car (keyless go) I heard the GRRRrrr of the SBC pump. So there you go.
MB World Stories
The Best of Mercedes & AMG
Manual Mercedes? 6 Times Sindelfingen Let Drivers Have All The Fun
Verdad Gallardo
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren
Verdad Gallardo
8 Classic Boxy Mercedes Designs That Have Aged Like Fine Wine
Verdad Gallardo
Flawlessly Restored Mercedes 190E Evo II Heads to Auction
Verdad Gallardo
Electric Mercedes C-Class Unveiled: 11 Things You Need to Know
Verdad Gallardo
Mercedes EQS Gets A Major Update: Everything You Need to Know
Verdad Gallardo
5 Underrated Mercedes-Benz Models That Don't Get the Love They Deserve
Verdad Gallardo
Mercedes 300D Has Pushed Well Past 1 Million Miles and It Ain't Stopping
Verdad Gallardo
10 Most Reliable Mercedes-Benz Models You Can Buy Used
Verdad Gallardo
MBWorld Fanatic!
Joined: Mar 2004
Posts: 5,017
Likes: 16
From: Ft. Lauderdale Area, USA
2015 ML 350
Originally Posted by aceman
unlock the car and it lowers itself - think its a german engineering design to make entering the car easier 
Happy holidays!
Aceman
Happy holidays!
Aceman
MBWorld Fanatic!
Joined: Mar 2004
Posts: 5,017
Likes: 16
From: Ft. Lauderdale Area, USA
2015 ML 350
Originally Posted by DarkStar
...my seat does move back when I open the door....
Out Of Control!!
Joined: Jul 2003
Posts: 15,901
Likes: 4,630
From: North Scottsdale, AZ
'71 Pinto
Originally Posted by Barry45RPM
How tall are you? I'm 6'2", I think I drive far enough back so that the car feels its good enough to get out, even though there is about 3 more inches of rearward travel available.
Re-sync (compliments of another forum member, posted a while back):
(1) Menu, key dependent must be off;
(2) Exit car with all windows and roof closed, lock the car;
(3) Wait a minute or so, open all windows and roof with the key;
(4) Close all windows and roof with key;
(5) Unlock and enter;
(6) Move the seat completely forward and back several times to reset memory;
(7) Menu, convenience, set steering & seat and key dependent;
Unfortunately because of so many complaints (IMO so many owners not knowing how to correctly setup and operate this feature) MBUSA removed the seat function from the easy entry/exit and only the steering wheel adjustment remains (CLS, 10/05 delivery).
Senior Member
Joined: Jul 2003
Posts: 412
Likes: 0
From: Bay Area
03 E55
Originally Posted by Barry45RPM
How tall are you? I'm 6'2", I think I drive far enough back so that the car feels its good enough to get out, even though there is about 3 more inches of rearward travel available.
Almost a Member!
Joined: Jul 2005
Posts: 47
Likes: 0
From: Texas
'06 E350, appearance/entertainment/ sunroof/DVD NAV/brilliant silver (C744)/Ash leather
Sources of noise
As indicated, this noise is most likely to come from the Sensotronic Brake Control System, in some occasions from the DC Airmatic, and is indeed absolutely normal:
The SBC system is functional as soon as it is “wakened” by:
• opening a door
• operating the central locking system
• depressing the brake pedal
• turning the key to position 1
• operating the parking brake
Activating SBC will:
• charge the accumulator (MOST LIKELY SOURCE OF NOISE !!)
• perform a Predrive Check
• move the pads towards the rotors with ~60 bar pressure
• erase the fault memory
The DC Airmatic wake-up occurs with any one of the following "inputs":
• key in the ignition
• open any doors
• open trunk lid
• activate parking brake
• pressing the brakes
Wake-up causes the DC Airmatic system to monitor vehicle ride height and adjust as needed dependent on vehicle load changes:
• if level is >30mm lower than normal (0mm +/-10) it will raise to normal level (if reservoir pressure >11 bar)
• if level is >65mm lower than normal, it will be raised even with a reservoir pressure of <11 bar by the compressor (prerequisite battery voltage >12.5v) to -63mm (critical level) (POSSIBLE OTHER SOURCE OF NOISE !!)
• if level is >10mm higher than normal, it will be lowered to normal
The SBC system is functional as soon as it is “wakened” by:
• opening a door
• operating the central locking system
• depressing the brake pedal
• turning the key to position 1
• operating the parking brake
Activating SBC will:
• charge the accumulator (MOST LIKELY SOURCE OF NOISE !!)
• perform a Predrive Check
• move the pads towards the rotors with ~60 bar pressure
• erase the fault memory
The DC Airmatic wake-up occurs with any one of the following "inputs":
• key in the ignition
• open any doors
• open trunk lid
• activate parking brake
• pressing the brakes
Wake-up causes the DC Airmatic system to monitor vehicle ride height and adjust as needed dependent on vehicle load changes:
• if level is >30mm lower than normal (0mm +/-10) it will raise to normal level (if reservoir pressure >11 bar)
• if level is >65mm lower than normal, it will be raised even with a reservoir pressure of <11 bar by the compressor (prerequisite battery voltage >12.5v) to -63mm (critical level) (POSSIBLE OTHER SOURCE OF NOISE !!)
• if level is >10mm higher than normal, it will be lowered to normal
