[1] Mass air flow sensor Sensor 2: The air mass is too large.

[1] Mass air flow sensor Sensor 2: The air mass is too large.

Test 1: Check component B2/5 (Hot film mass air flow sensor). Offset drift

1. Check component B2/5 (Hot film mass air flow sensor). Offset drift

Test 1.1: Check component B2/5 (Hot film mass air flow sensor).

Test 1.2: Read actual value of component B2/5 (Hot film mass air flow sensor).

Test 1.3: Check power supply of component B2/5 (Hot film mass air flow sensor).

Test 1.4: Signal wire Check component B2/5 (Hot film mass air flow sensor).

1.1. Check component B2/5 (Hot film mass air flow sensor).
Check component B2/5 (Hot film mass air flow sensor) using actual value.
Test prerequisite

- Engine at idle
Explanation of the following test

- During the test, the air mass must be in the green range.
Communication with ECU required

1.2. Read actual value of component B2/5 (Hot film mass air flow sensor).
Test prerequisite

- Engine at idle
- Blipping throttle
Status of relevant actual value:
- Air mass:Warning! Communication with ECU required.

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

- Engine at idle
- Air mass(530...585) mg/Hub
Question

- Is the actual value o.k.?


YES
The actual value is okay.Possible cause and remedy

- In the event of stored faults with a high fault frequency count or in the event of customer complaints, check lines and connectors for loose contact and corrosion..
End of test

NO
The actual value is not o.k.Possible cause and remedy

- Inspect component B2/5 (Hot film mass air flow sensor) for correct installation position.
- This test did not produce any clear result.
- Check power supply of component B2/5 (Hot film mass air flow sensor).


1.3. Check power supply of component B2/5 (Hot film mass air flow sensor).
Test prerequisite

- The actual value is not o.k.
Figure legend

- B2/5 (Hot film mass air flow sensor)
- B2/5b1 (Intake air temperature sensor)
- B2/5x1Plug connection Hot film mass air flow sensor
Test sequence

- Switch off ignition.
- Detach coupling at component B2/5 (Hot film mass air flow sensor).
- Measure direct voltage with multimeter between sockets [B2/5x1] 3 and [B2/5x1] 1
- Switch on ignition.
Specified value

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

- Switch off ignition.
- Measure direct voltage with multimeter between sockets [B2/5x1] 3 and [B2/5x1] 2
- Switch on ignition.
Specified value

- Voltage[11...14] V
Question

- Is the measurement value OK?







YES
The measurement value is OK.Possible cause and remedy

- Inspect component B2/5 (Hot film mass air flow sensor) for correct installation position.
- In the event of stored faults with a high fault frequency count or in the event of customer complaints, check lines and connectors for loose contact and corrosion..
End of test

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

- Test signal line between components N3/9 (CDI control unit) and B2/5 (Hot film mass air flow sensor) for Short circuit to positive.
- Signal line from N3/9 (CDI control unit) - B2/5 (Hot film mass air flow sensor) is faulty as a result of Short circuit to ground.
- Test ground cable of component B2/5 (Hot film mass air flow sensor) for Open circuit.
End of test

1.4. Signal wire Check component B2/5 (Hot film mass air flow sensor).
Test prerequisite

- The actual value is not o.k.
Figure legend

- B2/5x1Plug connection Hot film mass air flow sensor
Test sequence

- Switch off ignition.
- Connect 126-pole socket box at engine wiring harness.
- Measure resistance with multimeter between socket [1.85] 85 of the 126-pole socket box tester and socket [B2/5x1] 5
Specified value:

- Resistance <1 Ohm?
Question

- Is the measurement value OK?







YES
The measurement value is OK.Possible cause and remedy

- Inspect component B2/5 (Hot film mass air flow sensor) for correct installation position.


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

- Check lines from component N3/9 (CDI control unit) to component B2/5 (Hot film mass air flow sensor).
End of test