Part 2

No CAN message was received from control unit N93 (Central gateway control unit).


2.3.2.1.8. Check power supply at control unit A76 (Left front reversible emergency tensioning retractor).
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.
- The quiescent current is too high.Test quiescent current.
- If fault occurs again:Check alternator.
Do you want to continue with function 'Alternator test'?

YES
Note on alternator test; Depending 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

2.3.2.1.8. No further information available.


NO

2.3.2.1.8. No further information available.


NO
Test sequence

- Switch off ignition.
- Disconnect coupling 1 at component A76 (Left front reversible emergency tensioning retractor).
- Measurement at connector 1
- Measure direct voltage with multimeter between sockets (A76) 1.5 and (A76) 1.4
- Measure direct voltage with multimeter between sockets (A76) 1.5 and (A76) 1.6
Specified value

- Voltage[11.0 ... 14.5] V
Question

- Is the measurement value OK?


YES
The measurement value is OK.This test did not produce any clear result.Possible cause and remedy

- Inspect connector 1 at control unit A76 (Left front reversible emergency tensioning retractor) for damage, correct connection, loose contact and corrosion and repair, if necessary.
- A76 (Left front reversible emergency tensioning retractor)
End of test

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

- Line between component A76 (Left front reversible emergency tensioning retractor) and component F4f29 (Fuse 29)
- Line between component A76 (Left front reversible emergency tensioning retractor) and component W17/1 (Ground, left rear seat)
End of test

2.3.2.1.9. Check power supply at control unit A76/1 (Right front reversible emergency tensioning retractor).
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.
- The quiescent current is too high.Test quiescent current.
- If fault occurs again:Check alternator.
Do you want to continue with function 'Alternator test'?

YES
Note on alternator test; Depending 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

2.3.2.1.9. No further information available.


NO

2.3.2.1.9. No further information available.


NO
Test sequence

- Switch off ignition.
- Disconnect coupling 1 at component A76/1 (Right front reversible emergency tensioning retractor).
- Measurement at connector 1
- Measure direct voltage with multimeter between sockets (A76/1) 1.5 and (A76/1) 1.4
- Measure direct voltage with multimeter between sockets (A76/1) 1.5 and (A76/1) 1.6
Specified value

- Voltage[11.0 ... 14.5] V
Question

- Is the measurement value OK?


YES
The measurement value is OK.This test did not produce any clear result.Possible cause and remedy

- Inspect connector 1 at control unit A76/1 (Right front reversible emergency tensioning retractor) for damage, correct connection, loose contact and corrosion and repair, if necessary.
- A76/1 (Right front reversible emergency tensioning retractor)
End of test

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

- Line between component A76/1 (Right front reversible emergency tensioning retractor) and component F4f24 (Fuse 24)
- Line between component A76/1 (Right front reversible emergency tensioning retractor) and component W17 (Ground, right rear seat)
End of test

2.3.2.1.10. Check power supply at control unit A80 (Intelligent servo module for DIRECT SELECT).
Operation number of operation texts and work units or standard texts and flat rates:27-0641Test sequence

- Switch off ignition.
- Disconnect connector at component N15/5 (Electronic selector lever module control unit).
- Switch on ignition.
- Measure direct voltage with multimeter between 5 and 4
Specified value

- Voltage[7.0...16.0] V
Question

- Is the measurement value OK?







YES
The measurement value is OK.Possible cause and remedy

- Replace component A80 (Intelligent servo module for DIRECT SELECT).
Additional measures

- Perform initial startup.
- Continue with button "F2"







Initial startup
The following procedure will guide you through all steps required to perform a complete initial startup of system ISM.Preconditions

- The new control unit must have already been installed.
You will be guided through the following steps

- Detach transport protection.
- Perform calibration.
- Personalizing
- Activating
Start process with button F2.

Warning!Communication with ECU required.


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

- Check fuse f111 (voltage supply from control unit ISM) in component F58 (Engine compartment fuse and relay box).
- Check all affected plugs, connectors and electrical components for damage, loose contact, corrosion etc. and repair if necessary.
End of test







2.3.2.1.11. Check power supply at control unit A89 (DTR controller unit).
Check power supply at control unit A89 (DTR controller unit).
Figure legend

- A89 (DTR controller unit)
Test prerequisite

- The voltage test at component G1 (Battery) is o.k.
- Fuse 117 in component F58 (Engine compartment fuse and relay box) is o.k.
Test sequence

- Switch off ignition.
- Detach coupling at component A89 (DTR controller unit).
- 1.Measure direct voltage with multimeter between sockets 1 and 1.6
- Switch on ignition.
Specified value

- [11.0 ... 14.5] V
Question

- Is the value o.k.?







YES
Note

- 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..
End of test

NO
The measured value is not within the specified value range.Possible cause and remedy

- Cables between component F58 (Engine compartment fuse and relay box) and control module A89 (DTR controller unit)
- Plug connection MR4
End of test

2.3.2.1.12. Check power supply at control unit N2/7 (Restraint systems control unit).
Possible cause and remedy

- Overvoltage.Test battery.
- If fault occurs again:Check alternator.Communication with ECU required


2.3.2.1.13. Check power supply at control unit N3/9 (CDI control unit).

2.3.2.1.13. No further information available.


2.3.2.1.14. Check power supply at control unit N15/7 (Transfer case control module).
Test voltage supply of circuit 15.
Operation number of operation texts and work units or standard texts and flat rates:28-0641Test prerequisite

- Battery voltage is OK.
Test sequence

- Switch off ignition.
- Disconnect connector "A" at component N15/7 (Transfer case control module).
- Measure voltage in transmission wiring harness using a multimeter.
- Switch on ignition.
Measure direct voltage with multimeter between 5 and 3Specified value

- Voltage [8,0...16,5] V
Question

- Is the measurement value OK?







YES
Preconditions

- The measurement value is OK.
Other possible cause of fault

- Open circuit in power supply (circuit 30)
Additional measures

- Test voltage supply of circuit 30.
Continue with button "F2"

Test voltage supply of circuit 30.
Test prerequisite

- Battery voltage is OK.
Test sequence

- Switch off ignition.
- Disconnect connector "A" at component N15/7 (Transfer case control module).
- Measure voltage in transmission wiring harness using a multimeter.
- Switch on ignition.
Measure direct voltage with multimeter between 5 and 6Specified value

- Voltage [8,0...16,5] V
Question

- Is the measurement value OK?







YES
Preconditions

- The measurement value is OK.
Possible cause

- Replace component N15/7 (Transfer case control module).
Additional measures

- Perform initial startup.
Continue with button "F2"







Test 2.3.2.1.14.1: Initial startup with manual settings input for new control unit( For example: The previous control unit can no longer be read. )

2.3.2.1.14.1. Initial startup with manual settings input for new control unit( For example: The previous control unit can no longer be read. )
Initial startup with manual settings input for new control unit
The following procedure will guide you through all steps required to perform a complete initial startup of system VG.Preconditions

- The new control unit must have already been installed.
You will be guided through the following steps

- Program control unit.
- Determine vehicle data for off-line SCN coding from the vehicle.
- Perform off-line SCN coding.
- Calibrate control unit Transfer case.
Start process with button F2.

Warning:- Connect battery charger.- Make sure that the diagnostic plug is properly seated in the diagnostic socket.- The diagnostic connector must remain plugged in to the vehicle.- Switch off all electrical consumers.- If possible, do not perform any procedures on the vehicle during control unit programming.

Warning!Communication with ECU required.

NO
Preconditions

- The measurement value is not OK.
Possible cause

- Check fuse F87 (voltage supply from control unit N15/7 (Transfer case control module)) in component F33 (Rear backup fuse box).
- Inspect wiring and connectors at connection points for loose contacts, corrosion, damage and short circuits. Repair or replace as required.
End of test







NO
The measurement value is not OK.Possible causes

- Fuse F57 in component F4 (Load compartment fuse and relay box)
- Lines and connectors are defective.
Remedy

- Check fuse F57 (voltage supply from control unit N15/7 (Transfer case control module)) in component F4 (Load compartment fuse and relay box).
- Inspect wiring and plug connections between F4 (Load compartment fuse and relay box) and control unit N15/7 (Transfer case control module) for corrosion, loose contacts and damage.
End of test







2.3.2.1.15. Check power supply at control unit N15/9 (Rear axle differential lock control unit).
Operation number of operation texts and work units or standard texts and flat rates:35-0641Test prerequisite

- Battery voltage is OK.
Test sequence

- Switch off ignition.
- Disconnect connector at component N15/9 (Rear axle differential lock control unit).
- Measure voltage directly at the jacks of the wiring harness of the rear axle interwheel lock using a multimeter.
- Switch on ignition.
Measure direct voltage with multimeter between 47 and 46Specified value

- Voltage [9,0...16,0] V
Question

- Is the measured value within the specified value range?







YES
Test prerequisite

- The measurement value is OK.
Further test procedure

- Switch off ignition.
- Disconnect connector at component N15/9 (Rear axle differential lock control unit).
- Measure voltage directly at the jacks of the wiring harness of the rear axle interwheel lock using a multimeter.
- Switch on ignition.
Measure direct voltage with multimeter between 47 and 17Specified value

- Voltage [9,0...16,0] V
Question

- Is the measured value within the specified value range?







YES
Possible cause and remedy

- Internal fault in control unit
- Replace component N15/9 (Rear axle differential lock control unit).
Additional measures

- Perform initial startup.
Continue with button "F2"







Test 2.3.2.1.15.1: Initial startup with manual settings input for new control unit( For example: The previous control unit can no longer be read. )

2.3.2.1.15.1. Initial startup with manual settings input for new control unit( For example: The previous control unit can no longer be read. )
Initial startup with manual settings input for new control unit
The following procedure will guide you through all steps required to perform a complete initial startup of system VG.Preconditions

- The new control unit must have already been installed.
You will be guided through the following steps

- Program control unit.
Start process with button F2.

Warning:- Connect battery charger.- Make sure that the diagnostic plug is properly seated in the diagnostic socket.- The diagnostic connector must remain plugged in to the vehicle.- Switch off all electrical consumers.- If possible, do not perform any procedures on the vehicle during control unit programming.

Warning!Communication with ECU required.

NO
The measurement value is not OK.Possible causes

- Fuse F48 in component F4 (Load compartment fuse and relay box)
- Lines and connectors are defective.
Remedy

- Check fuse F48 (voltage supply from control unit N15/9 (Rear axle differential lock control unit)) in component F4 (Load compartment fuse and relay box).
- Inspect wiring and plug connections between F4 (Load compartment fuse and relay box) and control unit N15/9 (Rear axle differential lock control unit) for corrosion, loose contacts and damage.
NOTE

- After completing the repair work, always perform the following function check of system HAQ.
- After a successful function test is performed, the check is finished.
- If the function test was not successful, the possible causes and the measures to be taken will be shown.
Continue with button "F2"







Warning!Communication with ECU required.


NO
The measurement value is not OK.Possible causes

- Fuse F69 in component F4 (Load compartment fuse and relay box)
- Lines and connectors are defective.
Remedy

- Check fuse F69 (voltage supply from control unit N15/9 (Rear axle differential lock control unit)) in component F4 (Load compartment fuse and relay box).
- Inspect wiring and plug connections between F4 (Load compartment fuse and relay box) and control unit N15/9 (Rear axle differential lock control unit) for corrosion, loose contacts and damage.
NOTE

- After completing the repair work, always perform the following function check of system HAQ.
- After a successful function test is performed, the check is finished.
- If the function test was not successful, the possible causes and the measures to be taken will be shown.
Continue with button "F2"







Warning!Communication with ECU required.


2.3.2.2. Resistance test of engine compartment CAN

Test 2.3.2.2.1: Test total resistance of engine compartment CAN.

Test 2.3.2.2.2: Test terminating resistor of component X30/19 (Voltage distributor connector (CAN C), front passenger).

Test 2.3.2.2.3: Test terminating resistor of CAN element in control module N3/9 (CDI control unit).

2.3.2.2.1. Test total resistance of engine compartment CAN.

Test 2.3.2.2.1.1: Perform measurement at component X30/19 (Voltage distributor connector (CAN C), front passenger).

Test 2.3.2.2.1.2: Perform measurement at component N3/9 (CDI control unit).

2.3.2.2.1.1. Perform measurement at component X30/19 (Voltage distributor connector (CAN C), front passenger).
Test total resistance of engine compartment CAN.
Figure legend

- X30/19 (Voltage distributor connector (CAN C), front passenger)
Test sequence

- Switch off ignition.
- Measurement with multimeter
- (X30/19) 2.Measure resistance with multimeter between pins 2 and 2.1 (X30/19)
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 N3/9 (CDI control unit) to component X30/19 (Voltage distributor connector (CAN C), front passenger)
- Test terminating resistor of component X30/19 (Voltage distributor connector (CAN C), front passenger).
- Test terminating resistor of CAN element in control module N3/9 (CDI control unit).
End of test

2.3.2.2.1.2. Perform measurement at component N3/9 (CDI control unit).
Test total resistance of the CAN engine.
Test sequence

- Switch off ignition.
- Connect socket box to component N3/9 (CDI control unit).
- Measure resistance with multimeter between sockets (F.53) 23 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 N3/9 (CDI control unit) to component X30/19 (Voltage distributor connector (CAN C), front passenger)
- Test terminating resistor of component X30/19 (Voltage distributor connector (CAN C), front passenger).
- Test terminating resistor of CAN element in control module N3/9 (CDI control unit).
End of test

2.3.2.2.2. Test terminating resistor of component X30/19 (Voltage distributor connector (CAN C), front passenger).
Test terminating resistor of component X30/19 (Voltage distributor connector (CAN C), front passenger).
Test sequence

- Switch off ignition.
- Connect socket box to component N3/9 (CDI control unit).
- Disconnect coupling F at component N3/9 (CDI control unit).
- Measure resistance with multimeter between sockets (F.53) 23 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 X30/19 (Voltage distributor connector (CAN C), front passenger) to component N3/9 (CDI control unit)
- Component X30/19 (Voltage distributor connector (CAN C), front passenger)
End of test

2.3.2.2.3. Test terminating resistor of CAN element in control module N3/9 (CDI control unit).
Test terminating resistor of component N3/9 (CDI control unit).
Test sequence

- Switch off ignition.
- Connect socket box to component N3/9 (CDI 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.53) 23 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 N3/9 (CDI control unit)
End of test

2.3.2.3. Test procedure ground cable

Test 2.3.2.3.1: Measurement at component X30/19 (Voltage distributor connector (CAN C), front passenger)

Test 2.3.2.3.2: Measurement at component X30/46 (Rear end CAN C potential distributor connector)

2.3.2.3.1. Measurement at component X30/19 (Voltage distributor connector (CAN C), front passenger)
Test procedure ground cable
Figure legend

- Component X30/19 (Voltage distributor connector (CAN C), front passenger) is located in the front passenger footwell.
Test sequence

- Switch off ignition.
- Measurement with multimeter
- Unplug connector at component.
- Measure resistance with multimeter between socket (X30/19) 13.3 and ground (Kl. 31)
Specified value

- [< 5]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

- Check electrical lines and connectors for short circuit, open circuit, loose seating and damage using the appropriate wiring diagram.
End of test

2.3.2.3.2. Measurement at component X30/46 (Rear end CAN C potential distributor connector)
Test procedure ground cable
Figure legend

- Component X30/46 (Rear end CAN C potential distributor connector) is located behind the paneling in the left rear wheelhouse.
Test prerequisite

- Special equipment 'Code 430 (Offroad engineering package)' or 'Code 475 (Tire pressure monitor)' is installed.
Test sequence

- Switch off ignition.
- Measurement with multimeter
- Unplug connector at component.
- Measure resistance with multimeter between socket (X30/46) 1.3 and ground (Kl. 31)
Specified value

- [< 5]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

- Check electrical lines and connectors for short circuit, open circuit, loose seating and damage using the appropriate wiring diagram.
End of test

2.3.3. 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 X30/19 (Voltage distributor connector (CAN C), front passenger)
- Observe level voltage.
- Plug in connector again at connector strip X30/19 (Voltage distributor connector (CAN C), front passenger).
- 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

- X30/19 (Voltage distributor connector (CAN C), front passenger)
- Test connectors and wiring for CAN of engine compartment CAN control modules.
- Control unit
Communication with ECU required ( Measuring system )