Saturday, November 3, 2018

2010 Mercedes Benz C 300 (204.054) V6-3.0L (272.947) Page 2520


- Test terminating resistor of CAN element in control module N3/10 (ME-SFI [ME] control unit).



End of test



2.1.3.2.2.2. Test terminating resistor of component X30/5 (Left voltage distributor (CAN) connector).



Test terminating resistor of component X30/5 (Left voltage distributor (CAN) connector).



Test sequence



- Switch off ignition.



- Connect socket box to component N3/10 (ME-SFI [ME] control unit).



- Disconnect coupling F at component N3/10 (ME-SFI [ME] control unit).



- Measure resistance with multimeter between sockets (F.41) 11 and (F.54) 24 of the 35-pole socket box tester.



Specified value



- Resistor[115...125]ohms



Question



- Is the measurement value OK?



YES



The measurement value is OK.End of test



NO



The measurement value is not OK.Possible cause and remedy



- Line from component X30/5 (Left voltage distributor (CAN) connector) to component N3/10 (ME-SFI [ME] control unit)



- Component X30/5 (Left voltage distributor (CAN) connector)



End of test



2.1.3.2.2.3. Test terminating resistor of CAN element in control module N3/10 (ME-SFI [ME] control unit).



Test terminating resistor of component N3/10 (ME-SFI [ME] control unit).



Test sequence



- Switch off ignition.



- Connect socket box to component N3/10 (ME-SFI [ME] control unit).



- Connector F is plugged in at control unit.



- Unplug the socket F from the wiring harness at the socket box.



- Measure resistance with multimeter between sockets (F.41) 11 and (F.54) 24 of the 35-pole socket box tester.



Specified value



- Resistor[115...125]ohms



Question



- Is the measurement value OK?



YES



The measurement value is OK.End of test



NO



The measurement value is not OK.Possible cause and remedy



- Control unit N3/10 (ME-SFI [ME] control unit)



End of test



2.1.3.3. Test with the aid of the measuring system



Test sequence



- Measurement of level voltage of engine CAN buses CAN bus High and CAN bus Low with the universal oscilloscope



- Separating one user from the connector strip X30/5 (Left voltage distributor (CAN) connector)



- Observe level voltage.



- Plug in connector again at connector strip X30/5 (Left voltage distributor (CAN) connector).



- Repeat this procedure for all CAN users.



Specified value



- As soon as the faulty branch was disconnected, the current image of the level voltage changes.



Possible cause of fault in the faulty branch