srb1194

I've researched on the forums and feel comfortable that this gremlin is causing my problems with BAS & ESP Malfunctions. My questions is can I purchase this any place other than the dealer? Advance Auto has a Beck/Arnley switch. Is this the same the dealer sells or am I screwing up? I do have a dealer nearby but their prices have been outrageous on other products I've priced. I just don't want to take any chances in not fixing the problem. Any help would be appreciated.

Thanks.

srb1194

Signmaker

You will be fine with a Beck/Arnley switch and advance auto should even have a guarantee. They didn't have one for my year (2001) but I'm pretty sure they have it for an 03'. I ended up ordering mine from Rockauto.com...they have great prices!
Just be sure to bring in your old switch and compare to the new one so you don't have to make two trips like me...
Replacing mine fixed the BAS Warning and my cruse control.

srb1194

Thanks for the reply. Much to my surprise there is no stop light switch on my car as described in other threads. I lowered the panel and there are no wires going to the brake pedal mechanism at all. I hear a clicking noise from behind the rubber boot but there is no sign of a switch. I see where it is supposed to be mounted but the hole is empty. Any thoughts would be appreciated.

Thanks!

Signmaker

Hopefully someone with an 03' 320 will be able to chime in, but Im sure your car should have one.

Do the brake lights work like they should?

srb1194

Brake lights work perfectly. I'm just trying to eliminate the BAS & ESP malfunctions. Maybe I was lead in the wrong direction on other threads?

srb1194

Signmaker

I just read that the switch was moved in some cars (not specific ) to the other side of the firewall by the brake master cylinder. Its worth replacing because its fairly inexpensive ....usually around $20.
Have you had a brake job done recently? The wheel speed sensors have also been known to cause those warnings and are pretty easy to damage when replacing the brakes.
Hows you alignment?

srb1194

I've looked on the other side of the firewall and I see no such switch. The brakes were recently serviced by my local MB Mechanic. He does excellent work and I doubt he damaged anything in the process. Maybe I'm looking for something that doesn't exist. Any other ideas?

srb1194

LILBENZ230

Some of the later W203s do not have a brake light switch. They use a diaphragm inside the brake cylinder, IIRC.

srb1194

Thanks. Do you have any advice on the ESP BAS Malfunctions?

srb1194

Signmaker

Did this start to happen after brake service?

Wheel speed sensors can cause these warnings too. You could go to Advance Auto and have them pull the codes for free.... and that could pin point the problem before spending money you might not need to.

srb1194

I just purchased the vehicle and have no prior history to refer to. My local MB Service guy sold the car to me. I could ask him but I thought it was an easy repair and I would do it myself. That seems to be wishful thinking at this point.

MB124

What was the fix?

srb1194

Unfortunately there wasn't a fix. The BAS ESP malfunction appears at random times. My mechanic didn't find a specific problem. I still wish I knew. Things like this drive me NUTS! Any advice?

MB124

Have you had the car scanned with a STAR Scanner? The dealerships machine?

Have you checked the electrical connector on the ESP module for moisture/corrosion?
It is on the drivers side inner fender under the hood. These connectors had a tendency to leak and cause the kind of issues you are dealing with.

Mercedes put out a technical bulletin on this issue. Instead of pasting all of the info here is a link. Someone has already covered it here. https://mbworld.org/forums/c-class-w...y-cars-20.html about half way down the page you will see some pictures and the info you need to check this.

srb1194

My mechanic is certified through MB. When he read the codes he saw errors but nothing was repeatable. He said the cars sometimes give false malfunctions. I'll look at the connections you suggest if you could clarify their exact location. This could be the problem and I'd love to investigate it. Can you advise me?

MB124

Post # 500 on the link i gave you shows the exact location of the ESP module.
Check the connector going to it for corrosion.

MB124

Here is the link again. Go down to post #500. The picture shows the exact location.
https://mbworld.org/forums/c-class-w...y-cars-20.html

srb1194

That's fantastic. I'll take a look at it and report back. Thanks so much!

MW_ATL

If you look up the switch part with your VIN, if your car doesn't have it, it will show as an invalid part. I'd bet it is there, and the root of your problem!

I wrote up replacing this somewhere with pictures, it is pretty easy to get to. I would post a link, but on my phone and hard to do. If I were you I would double check, I don't believe the switch will grow any codes, it really does sound like it.

srb1194

According to the MB dealer my VIN doesn't have this switch? If I provide the VIN can someone cross reference this info? The VIN is WDBRF64J03F335626.