Operation CHARM: Car repair manuals for everyone.
Home >> Mercedes Benz Truck >> 2009 >> ML 320 BLUETEC (164.125) V6-3.0L DSL Turbo (642.820) >> Repair and Diagnosis >> A L L Diagnostic Trouble Codes ( DTC ) >> Testing and Inspection >> Manufacturer Code Charts >> 124600

Manufacturer Code Charts: 124600


The supply voltage to the sensors is outside the valid range.


Possible cause:

- Supply voltage
Affected functions:

- Power generation

-------------------------------------------------

Test 1: Supply voltage Test sensor 1.

1. Supply voltage Test sensor 1.

Test 1.1: If fault codes for several sensors are displayed at the same time, then one sensor has a short circuit to GND or to POS at the component or at the lead.

Test 1.2: Check component B28/8 (Pressure differential sensor (DPF)).

Test 1.3: Check component B28/5 (Pressure sensor downstream of air cleaner).

1.1. If fault codes for several sensors are displayed at the same time, then one sensor has a short circuit to GND or to POS at the component or at the lead.

1.1. No further information available.

1.2. Check component B28/8 (Pressure differential sensor (DPF)).
Check actual value B28/8 (Pressure differential sensor (DPF)).
Test prerequisite

- Ignition ON
- The air extractor system may not be connected to the exhaust system during the test.
Status of the relevant actual values:
- Coolant temperature:Warning! Communication with ECU required.

- Differential pressure Signal voltage:Warning! Communication with ECU required.
Specified value at coolant temperature between 10 °C and 85 °C

- Differential pressure Signal voltage464...682 mV
Specified value at coolant temperature < 10 °C or > 85 °C

- Differential pressure Signal voltage428...718 mV
Question

- Is the actual value o.k.?


YES
The actual value is okay.Figure legend

- B28/8 (Pressure differential sensor (DPF))
Further procedure

- Test wiring and plug connections between control module N3/9 (CDI control unit) and B28/8 (Pressure differential sensor (DPF)) for Loose contact, repair or replace if necessary.
End of test







NO
Check power supply of component B28/8 (Pressure differential sensor (DPF)).
Figure legend

- B28/8 (Pressure differential sensor (DPF))
Special tool

- Adapter cable611 589 03 63 00
Test prerequisite

- The actual value is not o.k.
Test prerequisite

- Switch off ignition.
- Detach coupling at component B28/8 (Pressure differential sensor (DPF)).
- Connect adapter cable no. 611 589 03 63 00 to engine wiring harness B28/8 (Pressure differential sensor (DPF)).
- Measure direct voltage with multimeter between sockets (B28/8x1) 2 and (B28/8x1) 3
- Switch on ignition.
Specified value

- Voltage[4.9...5.2] V
Question

- Is the measurement value OK?







YES
Check signal lines on component B28/8 (Pressure differential sensor (DPF)).
Figure legend

- B28/8 (Pressure differential sensor (DPF))
Special tools

- Test cable 266 589 01 63 00
- Socket box 129 589 00 21 00
- Adapter cable611 589 03 63 00
Test sequence

- Switch off ignition.
- Unplug connector of control module and component.
- Connect 126-pole socket box at engine wiring harness.
- Measure resistance with multimeter between socket (M.31) 31 of the 126-pole socket box tester and socket (B28/8x1) 1
Specified value

- Resistor<1ohms
Question

- Is the measurement value OK?







YES
The measurement value is OK.Further procedure

- Check signal line of component B28/8 (Pressure differential sensor (DPF)) for short circuit to positive.
- Check signal line of component B28/8 (Pressure differential sensor (DPF)) for short circuit to ground.
- Replace component B28/8 (Pressure differential sensor (DPF)).
Note

- Initialization is necessary after exchanging component 'B28/8 (Pressure differential sensor (DPF))'.
End of test

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

- Repair or replace faulty cable N3/9 (CDI control unit)- B28/8 (Pressure differential sensor (DPF)).
End of test

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

- Check voltage supply lines of component B28/8 (Pressure differential sensor (DPF)) as per wiring diagram.
End of test

1.3. Check component B28/5 (Pressure sensor downstream of air cleaner).
Check actual value B28/5 (Pressure sensor downstream of air cleaner).
Test prerequisite

- Ignition ON
IMPORTANT NOTE The air extractor system may not be connected to the exhaust system during the test.Status of the relevant actual values:
- B2/6b1 (Left intake air temperature sensor):Warning! Communication with ECU required.

- Intake air pressure:Warning! Communication with ECU required.

- Boost pressure:Warning! Communication with ECU required.
Specified value at a temperature < 10 C°

- With the ignition on, the values for intake air pressure and boost pressure may not deviate from one another by more than +/- 39 hPa.
Specified values at 10 - 85 °C

- With the ignition on, the values for intake air pressure and boost pressure may not deviate from one another by more than +/- 24 hPa.
Specified value at a temperature > 85 C°

- With the ignition on, the values for intake air pressure and boost pressure may not deviate from one another by more than +/- 39 hPa.
Question

- Are the read-out values OK?


YES
The actual values are okay.Further procedure

- Test wiring and plug connections between control module N3/9 (CDI control unit) and B28/5 (Pressure sensor downstream of air cleaner) for Loose contact, repair or replace if necessary.
End of test

NO
Voltage supply of component B28/5 (Pressure sensor downstream of air cleaner)
Figure legend

- B28/5 (Pressure sensor downstream of air cleaner)
Test prerequisite

- The actual values are not okay.
Test sequence

- Switch off ignition.
- Detach coupling at component B28/5 (Pressure sensor downstream of air cleaner).
- Measure direct voltage with multimeter between sockets (B28/5x1) 1 and (B28/5x1) 3
- Switch on ignition.
Specified value

- Voltage[4.6...5.1] V
Question

- Is the measurement value OK?







YES
Signal cable of component B28/5 (Pressure sensor downstream of air cleaner)
Figure legend

- B28/5 (Pressure sensor downstream of air cleaner)
Special tools

- Test cable 266 589 01 63 00
- Socket box 129 589 00 21 00
Test sequence

- Switch off ignition.
- Unplug connector of control module and component.
- Connect 126-pole socket box at engine wiring harness.
- Measure resistance with multimeter between socket (M.78) 78 of the 126-pole socket box tester and socket (B28/5x1) 2
Specified value

- Resistor< 1ohms
Question

- Is the measurement value OK?







YES
The measurement value is OK.Possible cause and remedy

- Replace component B28/5 (Pressure sensor downstream of air cleaner).
End of test

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

- Repair / replace faulty wiring between N3/9 (CDI control unit) and B28/5 (Pressure sensor downstream of air cleaner)
End of test

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

- Check voltage supply lines of component B28/5 (Pressure sensor downstream of air cleaner) as per wiring diagram.


1.3. No further information available.

pro multis · About Operation CHARM