B28 (Pressure sensor) : Short circuit to positive or open circuit (P0108)

The P0108 diagnostic trouble code indicates an issue with the pressure sensor (B28) and is caused when the Engine Control Module (ECM) detects a short circuit to positive or an open circuit in the sensor's wiring. Here are some steps that can help you fix the issue:

1. Inspect the wiring: Inspect the wiring harness that connects the pressure sensor to the ECM for any visible damage, such as cuts, chafing, or breaks in the insulation. Also, check the connectors for corrosion or debris. Repair or replace any damaged wires or connectors.

2. Check the pressure sensor: Check the pressure sensor for any visible damage, such as cracks or broken wires. If there is damage, replace the pressure sensor.

3. Check the power supply: Using a multimeter, check the voltage supply to the pressure sensor. The voltage should be within the specified range. If the voltage is too low, there may be a problem with the power supply or wiring to the pressure sensor.

4. Check the ECM: Use a diagnostic scanner that can read fault codes and access the data from the ECM to check if it is receiving a signal from the pressure sensor. If there is no signal, the ECM may be malfunctioning. Replace the ECM if it is found to be faulty.

5. Check the fuses: Check the fuses related to the pressure sensor system for any damage or blown fuses. Replace any damaged fuses.

6. Perform a road test: After performing the repair, take your vehicle for a road test to ensure that the fault code is not triggered again.

If the above steps do not resolve the issue, it is recommended to take your vehicle to a certified mechanic or dealership for further diagnosis and repair.

B28 (Pressure sensor) : Short circuit to positive or open circuit (P0108)

P0108
B28 (Pressure sensor) : Short circuit to positive or open circuit (P0108)
Possible cause:
­ B28 (Pressure sensor)
Affected functions:
­
Engine output
­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­
Test 1: Check component B28 (Pressure sensor).
1. Check component B28 (Pressure sensor).
Test 1.1: Check component B28 (Pressure sensor) using actual value.
Test 1.2: Test signal voltage of component B28 (Pressure sensor).
Test 1.3: Check power supply of component B28 (Pressure sensor).
1.1. Check component B28 (Pressure sensor) using actual value.
Test sequence
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Copyright ? 2013, ALLDATA
10.52SS
­ Switch on ignition.
Status of relevant actual value:
­ Intake manifold pressure (ADC):Warning! Communication with ECU required.
Specified values
­ Intake manifold pressure,Ignition ON: > 3.5 V
­ Intake manifold pressure,Operate engine at idling speed.:< 2 V
Question
­
Is the actual value o.k.?
YES
The actual value is okay.End of test
NO
The actual value is not o.k.Possible cause and remedy
­ Check power supply of component B28 (Pressure sensor).
­ Test signal voltage of component B28 (Pressure sensor).
Further possible causes of fault
­
Vacuum line
1.2. Test signal voltage of component B28 (Pressure sensor).
Figure legend
­ A ­ConnectionTest cable 35­pin socket box
­ 001 ­Sockets of component N3/10 (ME­SFI [ME] control unit)
­ 05 ­35­pin socket box
­ 050 ­126­pin socket box
­ 108 ­Test cable 266 589 01 63 00
­ N3/10 (ME­SFI [ME] control unit)
­ II 1­63ConnectionTest cable
­ III 64­126ConnectionTest cable
Warning!
­
­
Connection A of test cable 108 may NOT be connected to connection B of the 126­pin socket box (050).
Page 3692010 Mercedes Benz E 63 AMG Sedan (212.077) V8­6.3L (156.985)
Copyright ? 2013, ALLDATA
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Page 370
Figure legend
­ B28 (Pressure sensor)
­ 126/2 ­'Secondary air injection right bank of cylinders' shutoff valve
Test prerequisite
­ The power supply of component B28 (Pressure sensor) is OK.
Test sequence
­ Switch off ignition.
­ Connect the vacuum tester to the input of component B28 (Pressure sensor) with the 3 x distributor.
­ Connect socket box (126­pin) to component N3/10 (ME­SFI [ME] control unit).
­ Measure direct voltage with multimeter between sockets [ M.15 ] 15 and [ M.86 ] 86 of the 126­pole socket box tester.
­ Switch on ignition.
Specified values
­ Ignition ON: >3.5 V
­ Operate engine at idling speed.(Vacuum> 500 mbar):< 2 V
Question
­
Are the measurement values OK?2010 Mercedes Benz E 63 AMG Sedan (212.077) V8­6.3L (156.985)
Copyright ? 2013, ALLDATA
YES
The measurement values are OK.End of test
NO
The measurement values are not OK.Possible cause and remedy
­ Lines to component B28 (Pressure sensor)
­ B28 (Pressure sensor)
Further possible causes of fault
­ Vacuum line
End of test
1.3. Check power supply of component B28 (Pressure sensor).
Figure legend
­ B28 (Pressure sensor)
­ 126/2 ­'Secondary air injection right bank of cylinders' shutoff valve
Test prerequisite
­ The actual value is not o.k.
Test sequence
­ Switch off ignition.
­ Detach coupling at component B28 (Pressure sensor).
­ Measure direct voltage with multimeter between sockets (B28) 1 and (B28) 3
­ Switch on ignition.
Specified value
­ Voltage[4.75...5.25] V
Question
­
Is the measurement value OK?
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Copyright ? 2013, ALLDATA
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YES
The measurement value is OK.Further possible causes of fault
­
Test signal voltage of component B28 (Pressure sensor).
NO
The measurement value is not OK.Possible cause and remedy
­ Lines to component N3/10 (ME­SFI [ME] control unit)
End of test