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Home >> Mercedes Benz Truck >> 2012 >> R 350 4MATIC (251.157) V6-3.5L (276.958) >> Repair and Diagnosis >> A L L Diagnostic Trouble Codes ( DTC ) >> Testing and Inspection >> Manufacturer Code Charts >> C001 >> Part 2

Part 2


CAN controller: CAN bus OFF


1.3.2.1.5. Check power supply at control unit EZS.
Test prerequisite

- Battery voltage is OK.
- Fuse F34.f36 is OK.
Status of relevant actual value:
- Power supply:Warning! Communication with ECU required.
Specified value

- Power supply [11.0...14.5] V
Question

- Is the actual value o.k.?


YES
The actual value is okay.Possible cause and remedy

- In the event of stored faults with a high fault frequency count or in the event of customer complaints, check lines and connectors for loose contact and corrosion..
- Check alternator.
End of test

NO
The actual value is not o.k.Test sequence

- Switch off ignition.
- Detach sockets A and C at component N73 (EIS [EZS] control unit).
- Measure direct voltage with multimeter between sockets (N73) B.2 and (N73) C.1
Specified value

- Voltage [11.0...14.5] V
Question

- Are the measurement values OK?


YES
The measurement values are OK.Possible cause and remedy

- Inspect connector B,C at control unit N73 (EIS [EZS] control unit) for damage, correct connection, loose contact and corrosion and repair, if necessary.
- N73 (EIS [EZS] control unit)
End of test

NO
The measurement values are not OK.Possible cause and remedy

- Check lines between components N73 (EIS [EZS] control unit) and N10/1 (Driver-side SAM control unit with fuse and relay module) and repair or replace if necessary.
- Fuse and component F34 (Interior fuse box)
Continue with button F2

1.3.2.1.5. No further information available.

1.3.2.1.5. No further information available.

1.3.2.1.6. Check power supply at control unit A1 (Instrument cluster).

1.3.2.1.6. No further information available.

1.3.2.1.7. Check power supply at control unit N80 (Steering column module).

Test 1.3.2.1.7.1: Inspect control unit N80 (Steering column module) for undervoltage fault.

Test 1.3.2.1.7.2: Test voltage supply of circuit 30 by means of actual value.

Test 1.3.2.1.7.3: Test voltage supply of circuit 30 by means of measured value.

1.3.2.1.7.1. Inspect control unit N80 (Steering column module) for undervoltage fault.
If the fault code is not current, it may be deleted. In this case, the battery voltage was too low over an extended period.Charge the battery, if necessary.Question:Is the fault current in several control modules?Note:This fault could result in consequential faults. You should therefore process this fault first and then erase the fault memory.

YES
Possible cause and remedy

- Battery voltage too low.Test battery.Charge battery, replace if necessary.
- If fault occurs again:Check alternator.Communication with ECU required
- The quiescent current is too high.Test quiescent current.


NO
Manual check of supply voltage
Test prerequisite

- Fuse F34f33 (Fuse 33) in component F34 (Interior fuse box) is o.k.
- Actual value is not okay or there is a complaint.
Status of relevant actual value:
- Voltage at terminal 30:Warning! Communication with ECU required.
Test sequence

- Switch off ignition.
- Remove component Airbag.
- Please refer to WIS document AR91.60-P-0660.
- Remove component Multifunction steering wheel.
- Please refer to WIS document AR46.10-P-0100.
- Remove component A45 (Clock spring contact).
- Please refer to WIS document AR46.10-P-0200.
- This information can be shown using the help function (F6 button) in menu item 'Testing and repair work'.
- Measure direct voltage with multimeter between sockets [N80] 1.8 and [N80] 1.9
Specified value

- Voltage [11.0...14.5] V
Question

- Is the measurement value OK?













YES
The measurement value is OK.Possible cause and remedy

- Inspect connector 1 at control unit N80 (Steering column module) for damage, correct connection, loose contact and corrosion and repair, if necessary.
End of test

NO
The measurement value is not OK.Possible cause and remedy

- Plug connection at control unit N80 (Steering column module)
- Line between component N80 (Steering column module) and component W12 (Ground, center console)
- Line between component N80 (Steering column module) and component F34f33 (Fuse 33)
End of test

1.3.2.1.7.2. Test voltage supply of circuit 30 by means of actual value.
Test prerequisites

- Relevant fault codes exist or a complaint has been received.
- Battery voltage is OK.
- Fuse F34f33 (Fuse 33) in component F34 (Interior fuse box) is o.k.
Status of relevant actual value:
- Voltage at terminal 30:Warning! Communication with ECU required.
Specified value

- Voltage [11.0 ... 14.5] V
Question:

- Is the actual value o.k.?


YES
The actual value is okay.Possible cause and remedy

- If fault code 9010/9011 occurs without complaints or function faults, erase fault memory and perform a function check.
- In the event of stored faults with a high fault frequency count or in the event of customer complaints, check lines and connectors for loose contact and corrosion..
- Check alternator.
End of test

NO
The actual value is not o.k.Possible cause and remedy

- Test voltage supply of component N80 (Steering column module) by means of measured value.
End of test

1.3.2.1.7.3. Test voltage supply of circuit 30 by means of measured value.
Manual check of supply voltage
Test prerequisite

- Fuse F34f33 (Fuse 33) in component F34 (Interior fuse box) is o.k.
- Actual value is not okay or there is a complaint.
Status of relevant actual value:
- Voltage at terminal 30:Warning! Communication with ECU required.
Test sequence

- Switch off ignition.
- Remove component Airbag.
- Please refer to WIS document AR91.60-P-0660.
- Remove component Multifunction steering wheel.
- Please refer to WIS document AR46.10-P-0100.
- Remove component A45 (Clock spring contact).
- Please refer to WIS document AR46.10-P-0200.
- This information can be shown using the help function (F6 button) in menu item 'Testing and repair work'.
- Measure direct voltage with multimeter between sockets [N80] 1.8 and [N80] 1.9
Specified value

- Voltage [11.0...14.5] V
Question

- Is the measurement value OK?













YES
The measurement value is OK.Possible cause and remedy

- Inspect connector 1 at control unit N80 (Steering column module) for damage, correct connection, loose contact and corrosion and repair, if necessary.
End of test

NO
The measurement value is not OK.Possible cause and remedy

- Plug connection at control unit N80 (Steering column module)
- Line between component N80 (Steering column module) and component W12 (Ground, center console)
- Line between component N80 (Steering column module) and component F34f33 (Fuse 33)
End of test

1.3.2.1.8. Check power supply at control unit N71 (Headlamp range adjustment control module).
If the fault code is not current, it may be deleted. In this case, the battery voltage was too low over an extended period.Charge the battery, if necessary.Question:Is there a current undervoltage fault is several control modules?Note:This fault could result in consequential faults. You should therefore process this fault first and then erase the fault memory.

YES
Possible cause and remedy

- Battery voltage too low.Test battery.Charge battery, replace if necessary.
- If fault occurs again:Check alternator.Communication with ECU required
- The quiescent current is too high.Test quiescent current.


NO
Figure legend 1:N71 (Headlamp range adjustment control module)Figure legend 2:N10/1 (Front SAM control unit with fuse and relay module)Test prerequisite

- The relevant actual value is not okay.
- Battery voltage is OK.
- Fuse N10/1f51 (Fuse 51) is OK.
Test sequence

- Switch off ignition.
- Disconnect connector at component N71 (Headlamp range adjustment control module).
- Measure direct voltage with multimeter between sockets (N71) 20 and (N71) 19
- Switch on ignition.
Specified value:Voltage = [11.0...14.5] VQuestion

- Is the measurement value OK?













YES
The measurement value is OK.Figure legend 1:N71 (Headlamp range adjustment control module)Figure legend 2:N10/1 (Front SAM control unit with fuse and relay module)Possible cause or remedy in case of malfunction

- Inspect plug connections N71x1 and (N10/1) 24 for damage, loose contact and corrosion, and repair if necessary.
- N71 (Headlamp range adjustment control module)
End of test













NO
The measurement value is not OK.Figure legend 1:N71 (Headlamp range adjustment control module)Figure legend 2:N10/1 (Front SAM control unit with fuse and relay module)Possible cause and remedy

- Cable (N10/1) 24.1 - (N71) 19 is faulty .
- Cable (N71) 20 - W16/3 (Ground (left of component compartment, power ground)) is faulty .
- N10/1 (Front SAM control unit with fuse and relay module)
End of test













1.3.2.1.9. Check power supply at control unit N93 (Central gateway control unit).

1.3.2.1.9. No further information available.

If the fault code is not current, it may be deleted. In this case, the battery voltage was too low over an extended period.Charge the battery, if necessary.Note:This fault could result in consequential faults. You should therefore process this fault first and then erase the fault memory.Question:Is the fault current in several control modules?

YES
Possible cause and remedy

- Battery voltage too low.Test battery.Charge battery, replace if necessary.
- If fault occurs again:Check alternator.Communication with ECU required
- The quiescent current is too high.Test quiescent current.


NO
Test prerequisite

- Fuse o.k.
- Fuse o.k.
Test sequence

- Ignition: OFF
- Measurement at component
- Measure direct voltage with multimeter between ground socket and socket
Specified value

- Voltage[11.0...14.5] V
Question

- Is the measurement value OK?
( Picture : Example )







YES
Test sequence

- Unplug connector 8 at control unit N93 (Central gateway control unit).
- Measurement at connector 8
- Measure direct voltage with multimeter between sockets (N93) 8.1 and (N93) 8.6
Specified value

- Voltage[11.0...14.5] V
Question

- Is the measurement value OK?







YES
The measurement value is OK.Restore original status.

- Plug in the connector 8 at component N93 (Central gateway control unit).
- Switch on ignition.
End of test

NO
The measurement value is not OK.Possible cause and remedy in the case of undervoltage

- Lines between N93 (Central gateway control unit) and
- Lines between N93 (Central gateway control unit) and
End of test

NO
The measurement value is not OK.Possible cause and remedy

- Lines between and
- G1 (Battery)
- G2 (generator)
End of test

1.3.2.1.10. Check power supply at control unit Y3/8n4 (Fully integrated transmission control (VGS) control unit).
Operation number of operation texts and work units or standard texts and flat rates:27-0641Test sequence

- Switch off ignition.
- Separate plug connection at transmission.
- Measure voltage in transmission wiring harness using a multimeter.
- Switch on ignition.
Measure direct voltage with multimeter between 5 and 4Specified value:

- Voltage[8,5...16,4] V
Question

- Is the measurement value OK?







YES
The measurement value is OK.Possible cause of fault

- The conductors in the electrohydraulic control unit are interrupted.
- Component Y3/8n4 (Fully integrated transmission control (VGS) control unit) is defective.
Possible remedy

- Replace component Y3/8 (Electric control unit (VGS)).
Following the repair measures, the following checks MUST be carried out using the Diagnosis Assistance System, menu 'Initial startup'

- Initial startup with manual settings input for new control unit
End of test







NO

Test 1.3.2.1.10.1: The measurement value is not OK.

Test 1.3.2.1.10.2: Possible cause and remedy

Test 1.3.2.1.10.3: Test regulator and generator.

1.3.2.1.10.1. The measurement value is not OK.

1.3.2.1.10.1. No further information available.

1.3.2.1.10.2. Possible cause and remedy

1.3.2.1.10.2. No further information available.

1.3.2.1.10.3. Test regulator and generator.
Note on alternator testDepending on the engine variant, different alternators are installed.

- Alternators without networking
- Alternators networked with engine control unit
Networked alternators can be diagnosed via the engine control unit.Detailed information on alternator testing can be found in WIS.Press button F2 to go to WIS documents

1.3.2.1.10.3. No further information available.

1.3.2.2. Resistance test of engine compartment CAN

Test 1.3.2.2.1: Test total resistance of engine compartment CAN.

Test 1.3.2.2.2: Test terminating resistor of component X63/4 (CAN databus adapter connector, 2-pin).

Test 1.3.2.2.3: Test terminating resistor of CAN element in control module N3/10 (ME-SFI [ME] control unit).

1.3.2.2.1. Test total resistance of engine compartment CAN.

Test 1.3.2.2.1.1: Perform measurement at component X63/4 (CAN databus adapter connector, 2-pin).

Test 1.3.2.2.1.2: Perform measurement at component N3/10 (ME-SFI [ME] control unit).

1.3.2.2.1.1. Perform measurement at component X63/4 (CAN databus adapter connector, 2-pin).
Test total resistance of engine compartment CAN.
Figure legend

- X63/4 (CAN databus adapter connector, 2-pin)
Test sequence

- Switch off ignition.
- Measurement with multimeter
- (X63/4) 2.Measure resistance with multimeter between pins 2 and 2.1 (X63/4)
Adapter cable no. W220 589 00 99 36 may be used.Specified value

- [55...65]ohms
Question:

- Is the measured value within the specified value range?







YES
The measurement value is OK.End of test

NO
The measurement value is not OK.Possible cause and remedy

- Line from component N3/10 (ME-SFI [ME] control unit) to component X63/4 (CAN databus adapter connector, 2-pin)
- Test terminating resistor of component X63/4 (CAN databus adapter connector, 2-pin).
- Test terminating resistor of CAN element in control module N3/10 (ME-SFI [ME] control unit).
End of test

1.3.2.2.1.2. Perform measurement at component N3/10 (ME-SFI [ME] control unit).
Test total resistance of the CAN engine.
Test sequence

- Switch off ignition.
- Connect socket box to 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[55...65]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 N3/10 (ME-SFI [ME] control unit) to component X63/4 (CAN databus adapter connector, 2-pin)
- Test terminating resistor of component X63/4 (CAN databus adapter connector, 2-pin).
- Test terminating resistor of CAN element in control module N3/10 (ME-SFI [ME] control unit).
End of test

1.3.2.2.2. Test terminating resistor of component X63/4 (CAN databus adapter connector, 2-pin).
Test terminating resistor of component X63/4 (CAN databus adapter connector, 2-pin).
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 X63/4 (CAN databus adapter connector, 2-pin) to component N3/10 (ME-SFI [ME] control unit)
- Component X63/4 (CAN databus adapter connector, 2-pin)
End of test

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

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 X63/4 (CAN databus adapter connector, 2-pin)
- Observe level voltage.
- Plug in connector again at connector strip X63/4 (CAN databus adapter connector, 2-pin).
- 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

- X63/4 (CAN databus adapter connector, 2-pin)
- Test connectors and wiring for CAN of engine compartment CAN control modules.
- Control unit
Communication with ECU required ( Measuring system )

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