P203C

Fault of priority 1: fault of function monitor in electronic accelerator

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

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

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

Test 1.2: Test signal voltage of component B2/5 (Hot film mass air flow sensor) by means of actual value.

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

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

- AC off
- Temperature of coolant>70° C
- Engine at idle
Status of the relevant actual values:
- Air conditioning:Warning!
- Temperature of coolant:Warning! Communication with ECU required.
- Air mass:Warning! Communication with ECU required.
Specified values

- Air mass: [24.0...32.0] kg/h(If engine speed rises, the air mass increases.)
Question

- Are the actual values o.k.?


YES
The actual values are okay.Possible cause and remedy

- Replace control module N3/10 (ME-SFI [ME] control unit).
End of test

NO
The actual values are not okay.Possible cause and remedy

- Check power supply of component B2/5 (Hot film mass air flow sensor).
- Check lines from component N3/10 (ME-SFI [ME] control unit) to component B2/5 (Hot film mass air flow sensor).
- Unmetered air
- B2/5 (Hot film mass air flow sensor)


1.2. Test signal voltage of component B2/5 (Hot film mass air flow sensor) by means of actual value.
Test prerequisite

- Battery voltage is OK.
- Voltage supply of component B2/5 (Hot film mass air flow sensor): [11...14,5] V
- Engine OFF
- Ignition ON
Status of relevant actual value:
- HFM-SFI voltage:Warning! Communication with ECU required.
Specified value:

- Voltage [0,980...1,020] V
Question

- Are the measurement values OK?


YES
The actual values are okay.Possible cause and remedy

- Check assignment of component B2/5 (Hot film mass air flow sensor) to engine model designation.
End of test

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

- Check power supply of component B2/5 (Hot film mass air flow sensor).
- Check lines from component N3/10 (ME-SFI [ME] control unit) to component B2/5 (Hot film mass air flow sensor).
- 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.
Test sequence

- Switch off ignition.
- Detach coupling at component B2/5 (Hot film mass air flow sensor).
- Measure direct voltage with multimeter between sockets (B2/5) 3 and (B2/5) 2
- Switch on ignition.
Specified value

- Voltage[11.0...14.5] V
Question

- Is the measurement value OK?







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

- Unmetered air
- Signal wire
- B2/5 (Hot film mass air flow sensor)
End of test

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

- Cable for voltage supply
End of test