Lancelot

Replacing the brake light switch solved nothing! About half the time when I crank and start the car the warning stays on. When I turn the ignition off and recrank again the warning often goes away but sometimes not. It's mostly my wife's daily driver so I told her to restart like this until the warning stays off. A few weeks ago ASR safely held us out of serious trouble when we blew a rear tyre at 140km/h (87 Miles) during a trip in Belgium. What's the next step(s) can I take to diagnose this?

TMAllison

Is your replacement tire the "exact" same size and dia as the other three?

Does the warning come on if you turn ASR off?

Lancelot

Yes ofcourse I put on two new Michelins onto the rear rims. All four are now Michelin Energy 205/55/16 which are in spec for my 220Diesel. We've just been driving around and now the warning doesn't seem to go away anymore at all. Seems to me like there's a bad connection. or bad ABS sensor or what? What else can I check myself?

Lancelot

btw It cannot be the tyres cuz the warning comes on after cranking. Anybody ever went deeper into this than the brakelight switch?!

ohlord

should be oem tires.
Those warnings also come on when you have an under voltage condition.Battery not holding charge.Check battery charge loaded and no load,check alternator output,check your battery posts and cables for corrosion.Below 11.5 volts or so the warning lamps go off,and will shut off when charged or alternator provides correct voltage to system.

230TErry

Check the fuse holder in the side of the dash. If you wiggle the fuse and the warnings stay off you have a broken contact.

You will need a new fuse holder/headlight switch.

kstreufert

Another possibility is the brake booster. My E430 exhibited this problem at about 80,000 miles and a new booster corrected the problem. However if the booster is the cause the error would only occur after pressing the brake pedal after (or while) starting the car.

deno

I had same problem so I bought a second brake switch then it worked.

Lancelot

Your saying the first replacement switch you bought was defective?
The warning doesn't go away anymore right now. Today I measured the Voltage (at the battery terminals) and it's 12.5V with the engine off, and 13.9V with the engine running idle.

I think the next step would be removing wheel by wheel and check the wire coming from each ABS sensor...

01BlackE320

Is the problem triggered when you hit the brake pedal? My switch was replaced by the dealer under warranty some time ago. Every once in a while I still get the ABS BAS ESP but when it occurs, it's always triggered when the brake pedal is touched. It appears if there's a slight flicker in the switch when it is activated, it triggers the error. Restarting the car resets the error.

ohlord

travel can be adjusted.Some people purchase after market switches and it does not solve the problem,they get the upgraded mb switch and problem fixed.You can test the switch to see if it is the issue by back probing or jumper wire across the warning terminals in the smaller connector that connects to the brake switch.That is the one that triggers the abs warning.Start the car,if bad brake switch the warnings will no longer appear.
If they don't go out it could the brake booster or even dirt on the abs unit at a wheel.Your battery is good,the system has to drop below 10volts for that to trigger the lamps and if it was you would probably slip into limp mode.

Lancelot

Thanx Ohlord, I'm gonna try that out today (testing if it's the switch)
If not I'll drive over to a MB dealer to have any codes readout...

Semikolon

I usually get BAS, ABS and ESP warnings the first time I start the car after the battery has been disconnected. Also if it's low on power, but not as low as 10V. at 10V the starter wont even try to start the car, it just makes a click and stops (I've tried). The car does not go into limp mode. After a few minutes the lights disappears and everything is in working order, even without stopping and starting the car again.

BTW, did you buy a new facelift 210 or is your avatar a german promo picture? It looks hot

Lancelot

I did the test Ohlord suggested, bridged the small connector and most of the time the warnings stayed off, but sometimes not. With the connector hanging loose and unbridged I noticed only the BAS-ASR light came on.

Just to be sure I got another new brakelight switch (worth a try for €15.-) but all the warnings still come up most of the time after cranking. On my way to and from the dealer I noticed the cruisecontrol wasn't working anymore!

I checked and reseated all the fuses in the electronic-box under the hood, on the left side of the dashboard and under the rear seat.

I even disconnected the battery for like 15mins. hoping to reset something, but the warninglights still come up. *sigh* However after disconnecting the battery the cruisecontrol is working again!?

By the time I was done doing all the above it was too late to head back to the MB dealer, so I'll have the codes read next week...

sandro

My 96 320 had the same problem for a long time my friend. I can say that buying a factory OE MB brake switch is a MUST. I went through several switches before I got the problem solved. Also, my mechanic told me to try turning the steering wheel all the way to the right, then all the way back to the left, just after startup, while the car is in park. Good luck with this one but for sure use ONLY MB FACTORY BRAKE SWITCH

Lancelot

Guys I only got OEM switches from the MB dealer. In my case it's clearly NOT the switch. I took one apart and there are simply two sturdy contacts inside. One for the brakelights and the other for the electronics. These are both closed when the brakepedal is touched. I can understand this may fail sometimes with an 11y/o switch but not with a new one! I'm going to have any codes read out next saturday at a dealer. Without that I'm not going to get any further...

Lancelot

No my avatar isn't a German promo picture, lol! It's just a model '98 E220D with 'elegance' trim. (a European package) I just took this picture out of my bedroom window...



As you can see it's a nice and clean car, and that's why I want to keep everything in good working order!

Semikolon

It was meant for ohlord

deno

My problem with brake switch came down to needing a new light switch at a cost of 300 hundred but problem finally fixed. so if the brake switch dosen't work look into light switch.

01BlackE320

Thanks for letting us know. The Germans design spectacular cars, with the exception of being able to "screw in a lightbulb" without triggering an ABS error.

Lancelot

*Update* codes have been read at MB dealer and stardiag states:

ASR section:
C1200 S9/1 (Stop lamp switch): Plausibility
C1011 Power supply A7/3 (Traction system hydraulic unit)
C1315 (no error text found)

BAS section:
C1225-003 Fault in CAN communication with control unit N47-7 (ABS control module). If no user complaint exists, the fault can be erased.
C1207 S9/1 (Stop lamp switch): Plausibility

(Then a *****load of codes from the airbag system to the Pneumatic system equipment about suplly voltage too low. This must be due to a dead battery a few weeks ago.)

According to the dealer these codes are triggered whenever the ABS/ASR module receives 9.0V or lower right after cranking and engine start. It's a stored code, not an actual code, but upon resetting, this 'stored' code comes back up again. This can be just about anything, including lightswitch or the ASR module is failing itself.

I told them to leave it for now, as the diff has been overhauled and a few other things already costing me $$$ I think I'm gonna contact a MB specialized scrap yard and ask them if I can try (exchange) another ASR module first. (no cure, no pay ofcourse)

wtwoten

https://mbworld.org/forums/e-class-w...s-problem.html

so a year and a half later and my car still has all of these lights on. ive gone through numerous steps suggested by my indie and the board but nothing has worked. hopefully you have better luck than me.