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2003 s430 esp bas pre safe inactive brake booster ?

7K views 12 replies 10 participants last post by  04S600AMG 
#1 ·
took my 2003 s430 to the dealer after getting 3 malfunctions, pre safe inactive, bas off , esp off. They told me i have a faulty brake booster. but i dont believe that, the car drives perfectly and brakes just fine, when the malfunctions are on or even after i restart the car and it goes back to no malfunction. is there some sensor that could be causing this ?? thank guys let me know please. car only has 53k miles on it
 
#5 ·
More specifically, losing voltage to the steering angle sensor causes it to "forget" where center is. As suggested, do the reset and that SHOULD re-establish center if there is nothing else wrong.
 
#7 ·
Do you guys even know what bas is? There's a solonoid in the booster that will apply the brakes for you.


The Brake Assist System (BAS), an electronic system by Mercedes-Benz, interprets the braking behavior of the driver and initiates the full braking effect when it identifies an emergency situation. This reduces the braking distance substantially.

In essence, you still have to apply the brakes. They are not intuitive.
 
#9 ·
Side note about BAS. Having some track experience from my younger years I did not pay attention to stuff of this kind, and driving MB for about 20 years don't think I ever used the feature.
Than (might be sign of aging) in last year I overlooked the situation twice and had to activate BAS. Now I am glad I had the option.
 
#11 ·
My understanding is that the car interprets a sudden and hard brake application as an emergency situation. Mercedes research showed that most drivers do not apply the brakes hard enough in such a situation, and that extra brake application can prevent, or lessen the effects of, an accident. The BAS applies sufficient brake pressure to activate the ABS, and holds the pressure until the brake pedal is released.
 
#13 ·
I have been having this same fault in my 2004 S600 for about 6 months. Until I found this thread I couldn't get a straight answer. Now it makes complete sense. 99 out of 100 times when I get the fault all I get is the dash messages (BAS Error, ESP Error, and PreSafe Error) all at the same time and ALWAYS all three. However there have been at least 2 times where I touched the brakes and all of a sudden they would go full on for split second then release. I just chalked it up to me pressing harder than I thought I had. Now that you have explained the BAS function I know where to concentrate my trouble shooting.

Thank you,

Brian
 
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