Following up on my earlier post. I drove down the I-5 around 40 miles today and when I was in the far left lane the car behaved flawlessly. As soon as I went over to the center or right lane I could get the Collison Avoidance to trip on at least 4 occasions. It is always when another car is overtaking me on the left, they are 10 feet away from me in my blind spot on almost all of the occasions and it trips. The car is basically un-drivable on the freeway at this point. I am taking it in on Monday to the MB dealer and they are going to take a look at it. I talked to my long time service advisor and told him what was going on and he indicated that it absolutely should not be doing that. Because it is only on the drivers side I have to wonder if a sensor is out of whack on that side or even malfunctioning. Really hope they can fix it but worried about them having the parts needed to fix it. Bummer that such an expensive car is having this kind of an issue.

 

Funny, I just picked my S560 from the dealer after having the engine and trans mounts replaced. Dealer had also just washed the car and it was waiting for my pickup. The temperature outside is -2.5 C and as I was driving home about 3 miles from dealer, all my "Active Assist. functions became 'inoperative'
I called the dealer as soon as I got home and he feels that maybe the car wash froze the sensors and to wait a few hours to see if matter resolves.Hope so.
Follow up: just returned from the dealer and while they checked it in shop, maybe the warm garage unfroze the freezing water from car wash because all is fine now.
WARNING! Whenever you take your car to a car wash, assume that the sensors may freeze and if going to a self car wash, avoid spraying directly at the sensors on the body and grill.

 

Good advice and on top of that, try not to wash your vehicle in below freezing temperatures as sudden cold water (or not warm enough, some car washes just simply use cold water as far as I heard) on hot vehicle components may cause stress and may cause cracks to develop in some sensitive parts. It doesn't always happen but the risk is increased at those temperatures.

 

Thanks for your inputs , that advice definitely makes sense a lot .

 

It is puzzling to read reports about being brushed off by MBUSA when they decline to make good on "the best or nothing" pitch. Dealers have all the tools and ressources to make these cars reliable when given time...


Has anyone found the key to this puzzle with a working repair, a TSB publication or by using Xentry to scan the car....?

I wouldn't be surprised if the faults appeared randomly due to networking issues unspecific to one radar (replacing sensor may provide NO relief). Faulty connections create high packet retransmits...

Considering also digital sensors rely on analog signals that are affected by noise glitches. Xentry uses "adaptations" to preset working thresholds.

We could use a pair of eyes with a scanner...
👀

 

Well, I picked the car up and they could find nothing wrong. They did turn off the BSM system and that seems to have fixed it in the limited driving I have done since before it was in the shop. I am sure if I turn the BSM back on it will do the same thing randomly but I have not tried this yet with all of the rain we have right now. I am going to wait until we have dry weather and then turn the BSM back on and see if I can replicated the erratic braking and behavior that happens with it on. At least I think I have narrowed down the problem. I would guess it is a bad radar sensor in the drivers side rear bumper that is the culprit but they told me they checked that. Next time I am going to drag the tech out on the freeway with me and show them exactly what is happening. It is only on the drivers side, only when the BSM is turned on and only when a car is passing me randomly.

 

Yes Suppp, bingo!
I only have a modest knowledge of MB but I already know these rear blind spot modules get oxidized by rain intrusion.

Switching off the related menu option won't keep failed modules from screwing the CAN bus signaling....
In a pinch, I would UNPLUG THEM and tape the connectors to stop further oxidization.


Poker face:
I find it unbelievable no fault could be found to troubleshoot this scary failure.... Is this denial of service or dangerous lies?

Replacing new modules plus new harness without added protection will yield same results. Seal the connector with silicone grease inside and silicone RTV outside.
Don't be surprised with other external connectors developing similar issues. Seal exposed connectors preventively.

DIY...
Once you grow tired of the run-around game... is when some of us put a pair of gloves on to save time & bundles.

PLAN B:
I wonder what the service clerk would say if you specifically asked to get these modules replaced and sealed...

BTW internal BSM connector pins also happen to be solderless ie. unreliable connections likely to come into play with random faults.... easily fixed by soldering.
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Been driving the car now for a few weeks with the active blind spot monitor system turned off and it is not done this odd behavior once. I have to think it is a bad sensor or connection in the drivers side rear bumper. I am going to take it to a different dealer and see if they can do anything to fix this. The passenger side Active BSM works fine, it is only the drivers side.

 

Update, took it to a different dealer and they witnessed the issue. Took them 3 weeks to fix but they ended up replacing one rear radar sensor and the harness for both sensors. Seems to be working fine now.

 

Wow, congrats you called it!

 

Nice to hear they got it fixed

 

Have you ever figured out what the issue was?
I have a similar issue with my 2007 S550 4matic; in 10-25% of the times I brake (lights, etc.), the beep comes on and Park Assist lights up, and then goes off; no code is stored...
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First thing to do with these case is scan with Xentry and DTS
DTS give more information than Xentry as Das Developer gives more informations as DAS
Often DTS shows faults not shown in Xentry (the hidden faults)

Then see if all the involved modules have latest SW, if so, I update them, check codings
Check / redo calibrations,
Then search for TSB and MB notes in MB servers
Then execute several tests


Only after all this it's reasonable to think that there is a hardware failure

Keep in mind that MB Dealers use the "Let's replace all" politics
after all, it's your pocket