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Monday morning on my way to work, my speedomer display began to alternate warnings about problems with ABS, ESP and BAS. It showed them as three seperate malfunctions, but they all occured at once. I made an appointment with my mechanic for Wednesday morning, but the next time I started the car, the warnings were gone. Unfortunately, my mechanic's system can't read the log from the cars computer and they suggested going to the dealer. I'd like to exhaust all options before taking that frustrating step. Is this a problem anyone else has experienced and knows the cause and cure?

PS It hasn't happened again since...
 

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Codes should be stored. Any shop with a quality scan tool should be able to retrieve them to point them in the right direction for diagnosis. A dealership or any competent and respectable independent shop should be able to help you out fairly easily.
 

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I had warning lights for bas/esp and was advised to replace $18 brake switch and lights are now off 15 minute repair. I was told very common on 202 body.
 

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BAS malfunction

we had the same problem on our c240 2001 . got a check engine lite on the dash a few weeks ago and upon taking it to my longtime mechanic, was told the codes it showed meant i needed a new MASS AIR sensor.
no problem , seemed to do the trick check engine gone. we had VERY few problems/errors with this car but now get a recurring BAS "brake assist" malfunction almost every day (not today though) . at one point , i know that the battery was disconnected when in for service. plus i just had all 4 brakes done 2 months ago.
what exactly is BAS and how crucial is it , or does it require IMmEDIATE service?
please teach me.....thanks!
 

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BAS lights and Check engine lights are different. If your mechanic used a generic scanner he will only get the OBD II codes for engine troubles like Mass Airflow Sensor. My BAS was a simple brake light switch. You need to have the codes pulled from the appropriate ECU to diagnose the light.
 

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The brake switch is at the top of the brake pedal. I believe it is either snapped in place with a plastic clip or held in with one nut. easy repair with no special tools needed. maybe a 13 or 15mm wrench.
I think the part was $15 and it took me 10 minutes to replace.
GGOD LUCK HOPE IT FIXES THE PROBLEM! VERY COMMON!
 

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What are the odds that both things failed at the exact same time without a common cause?
I had three fault codes show up at the same time: BAS, Teleaid, and ESP. These codes would come and go with subseqent starts (but mostly only two of them at a time) I don't have Teleaid so was suprised it was throwing a fault. In my case, it turned out that the original battery was on it's last leg, and a few days later failed to start the car. Upon replacing the battery, no fault have been detected, and no wasted money on replacement of brake switches, or modules.
How old's you battery? Most OEM Benz batteries won't last more than four years. I'd check the battery condition, before anything else. '

P.S. The bad battery never caused a battery or low voltage fault code, and on one start-up, put the tranmission control module into a fault, which limited the auto transmission to only second gear "limp home mode". I put a trickle battery charger on the "jump start" terminals before replacing battery, to avoid the memory, radio, etc. resetting.

Good Luck,

Brad
 
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