[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 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.85) 85 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. No further information available.