P20B7

B28/4 (Pressure sensor downstream of air cleaner, left cylinder bank)

Test 1: Check component B28/4 (Pressure sensor downstream of air cleaner, left cylinder bank).

1. Check component B28/4 (Pressure sensor downstream of air cleaner, left cylinder bank).
Note

- Components B28/4. B28/5. B28/6. and B28/7 are identical in design and differentiated by a colored marking.
ComponentB28/4 (Pressure sensor downstream of air cleaner, left cylinder bank)/B28/5 (Pressure sensor downstream of air cleaner, right cylinder bank)

- Marking 'Green'
ComponentB28/6 (Pressure sensor upstream of throttle valve)/B28/7 (Pressure sensor downstream of throttle valve)

- Marking 'Blue'
Continue with button F2

Note

- If the pressure difference at full load from component B28/4 (Pressure sensor downstream of air cleaner, left cylinder bank) to component B28/5 (Pressure sensor downstream of air cleaner, right cylinder bank) is greater than 50 hPa, there may be dirt on the screen upstream of component Air cleaner, left cylinder bank or Air cleaner, right cylinder bank, or in component Air filter.
Continue with button F2

Test 1.1: Check power supply of component B28/4 (Pressure sensor downstream of air cleaner, left cylinder bank).

Test 1.2: Check component B28/4 (Pressure sensor downstream of air cleaner, left cylinder bank) using actual value.

Test 1.3: Test signal voltage of component B28/4 (Pressure sensor downstream of air cleaner, left cylinder bank).

1.1. Check power supply of component B28/4 (Pressure sensor downstream of air cleaner, left cylinder bank).
Test prerequisite

- The actual value is not o.k.
- The power supply of component N3/10 (ME-SFI [ME] control unit) is OK.
Test sequence

- Switch off ignition.
- Detach coupling at component B28/4 (Pressure sensor downstream of air cleaner, left cylinder bank).
- Measure direct voltage with multimeter between sockets (B28/4) 1 and (B28/4) 3
- Switch on ignition.
Specified value

- Voltage[4.75...5.25] V
Question

- Is the measurement value OK?


YES
The measurement value is OK.Further possible causes of fault

- Test signal voltage of component B28/4 (Pressure sensor downstream of air cleaner, left cylinder bank).
End of test

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

- Lines to component N3/10 (ME-SFI [ME] control unit)
- N3/10 (ME-SFI [ME] control unit)
End of test

1.2. Check component B28/4 (Pressure sensor downstream of air cleaner, left cylinder bank) using actual value.
Warning!Communication with ECU required.


1.3. Test signal voltage of component B28/4 (Pressure sensor downstream of air cleaner, left cylinder bank).
Test prerequisite

- The power supply of component B28/4 (Pressure sensor downstream of air cleaner, left cylinder bank) is OK.
Test sequence

- Switch off ignition.
- Connect socket box (126-pin) to component N3/10 (ME-SFI [ME] control unit).
- Measure direct voltage with multimeter between sockets [3.4] 37 and (3.23) 56 of the 126-pole socket box tester.
- Switch on ignition.
Specified values

- Ignition ON: [3.5...4.0] V
Question

- Are the measurement values OK?


YES
The measurement values are OK.End of test

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

- Lines to component B28/4 (Pressure sensor downstream of air cleaner, left cylinder bank)
- B28/4 (Pressure sensor downstream of air cleaner, left cylinder bank)
Further possible causes of fault

- Air cleaner dirty
End of test