lesnagy

2012 ML350 Bluetec, emissions recall performed about 5 months ago.
I have been error code free for months. Last week the blind spot inopt notice popped up. First dealer said the sensors are on a 2 year back order then said they could get them and it will be $3000 CAN to replace.
next day my systems went haywire on the highway, traction control inopt, parking brake alert, cant shift transmission. I shut it down and all can back normally with still blind spot inopt error. Dealer said removing the sensors will stop CAN bus messaging. Senders removed and for a day it was fine with just BSpot inopt error. One night in the garage and the computer lost its mind. traction control, ABS, engine light, parking brake light etc all inopt. Dealer said disconnect the harness at the connector on driver side under fender. I did that and also disconnected the battery for a while. No change the system is still running rampent with CAN bus issues. I think the CAN bus needs to be terminated due to the sensors being gone at this point. Is there a termination resistor needed or should the sensor harness be cut and loop back the wires in some logical way? No clue what way to go with this but with huge snow storm its a show stopper to not have traction control and ABS braking function.
FYI one of the sensors was bulging and when I opened it up it was packed with corrosion. Fun fact. This was a California car till just six months ago and it never saw winter. This year is the first winter ever and I am shocked that this sensor is toast. Livid with mercedes at the moment. Don't even get me started into the fact that it took a dealer 5 months to complete my emissions recall work.

bbirdwell

Can you code out the sensors? That way the system is not expecting to see the sensors so it should ignore an open connector.

CaliBenzDriver

You have very interesting questions.
Now that your swampy radar sensors are literally out of the CAN loop, your car should no longer be acting up.

Do yourself a favor and use a scanner to lists all DTC faults. It won't point to a fix but will help you focus where computers need help.


> Some basics pointers:

• Clean all your painted GND posts
• Monitor driving voltage for sudden drop to 11.xV
• Scan chassis for DTC's collection.
• Scope related chassis CAN-E ?
• RTV the exposed Benz "sealed connectors"
• Learn the specific class of Easter-Eggs built into your cha$$i$.
• Be proactive with maintenance care
• keep these cars out of rain as much as possible.

> CAN bus resistors:
I found 1x 60.R resistor actually installed in distribution blocks located under both side front carpets. Previous belief was 2x 120.R at two extremities... Bosch rewrote its books: one single 60.R in the middle.

So unplugged BS radars do not cause additional CAN B/E instabilities.
Owning a Mercedes to deal with the many different types of CAN disruptions possible is an interesting quest. This is the ultimate game ✌️

> Water killer expansion:
- Road splashed water loged Radars literally crack their shell opened when water freezes inside.
- Do seal the harness connector of these otherwise pretty good units.

MBENZTECH

Having the sensors disconnected should not have an impact on the rest of the systems, only Blindspot message should be displayed. I think you might have some other issues.