CanBus Reliability Testing

[MobyMidge]

I have a 2006 R230.456 with intermittent ESP/SBC can bus connection issues. I don't have Xentry yet (need more posts and likes ) but can you test the reliability of your can bus connections/wiring using Xentry? I have had water ingress in the passenger side foot well which resulted me having to repair connections to 2 can bus distributors and I want to rule out these connections before purchasing a replacement ESP module.

 

[fetteblutzn]

You can check the busbar signal via oscilloscope. one connection of the probe to the busbar to pick up the signal, one to the chassis (Ground / negative terminal of batterie) then unplug every plug until your intereference dissappears. once you figured out what connection might be the problem, check the spades (pins in the plug/Busbar for corrision, you might aswell follow the the wire with a line finder and check on the other side. Mostly the busbar in the footwell is the problem. I also have problems with corrosion inside plug that went into the cable multiple cm's into the wiringharness - on a 2013 car.

 

[MobyMidge]

Thanks for this, I will get my old oscilloscope out. I also think the footwell is where the issue lies.

 

[etronic]

You can by-pass CAN with good ones to check if your water-damaged ones are causing faults

 

[MobyMidge]

So far I have checked out the Can Bus with an oscilloscope and the trace looks normal. I have also redone all the connections in the footwell.

From reading other forums, many owners have experienced similar (not exactly the same) issues and the rear consumer battery has been the cause. I have now charged it up but my Topdon BT100 is only reporting 65% health but 100% charge. I need to take it for another drive but it is frightening when the brakes go especially in traffic which is hard to avoid where I live.

 

[Tazmania]

Between the SBC and the ESP there is a private CAN just like the W211, they can be checked just like the normal CAN for continuity with a resistance tester or if they have approximately 2.5V with the ignition on, I would also check the power supplies of the two SBC and ESP

 

[MobyMidge]

Between the SBC and the ESP there is a private CAN just like the W211, they can be checked just like the normal CAN for continuity with a resistance tester or if they have approximately 2.5V with the ignition on, I would also check the power supplies of the two SBC and ESP

Thanks for the information, I need to find the wiring diagram so I can identify the pinouts

 

[Tazmania]

post your VIN number.

 

[MobyMidge]

post your VIN number.

WDB2304562F120065

 

[Tazmania]

WDB2304562F120065

SBC and ESP wiring diagram W230