[4] Check component B28/5 (Pressure sensor downstream of air cleaner).: CAN signal faulty

[4] Check component B28/5 (Pressure sensor downstream of air cleaner).: CAN signal faulty

Test 1: Check component B28/5 (Pressure sensor downstream of air cleaner).

1. 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
Status of the relevant actual values:
- Boost pressure:Warning! Communication with ECU required.

- Atmospheric pressure:Warning! Communication with ECU required.

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

- With the ignition on, the values for boost pressure, atmospheric pressure and intake air pressure must not deviate from one another by more than 30 hPa.
Question

- Are the read-out values OK?


YES
The actual value is okay.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)
Test prerequisite

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

- Voltage[4,6...5,1V]
Question

- Is the measurement value OK?


YES
Signal cable of component B28/5 (Pressure sensor downstream of air cleaner)
Special tools

- Test cable 271 589 00 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 [1.13] 13 of the 126-pole socket box tester and socket [B28/5x1] 2
Specified value:

- Resistance <1 Ohm?
Question

- Is the measurement value OK?


YES
The measurement value is not OK.Possible cause and remedy

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

NO
The measurement value is OK.Test signal line between components N3/9 (CDI control unit) and B28/5 (Pressure sensor downstream of air cleaner) for Open circuit.End of test

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

- Test lines between components N3/9 (CDI control unit) and B28/5 (Pressure sensor downstream of air cleaner) for Open circuit.


1. No further information available.