2010 Mercedes Benz C 300 4MATIC (204.081) V6-3.0L (272.948)
A L L Diagnostic Trouble Codes ( DTC ): Manufacturer Code Charts 0537
B2/5 (Hot film mass air flow sensor)
Possible cause:
- B2/5 (Hot film mass air flow sensor) Affected functions:
- Engine output
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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 signal of component B2/5 (Hot film mass air flow sensor) via actual value with engine OFF.
Test 1.2: Check signal of component B2/5 (Hot film mass air flow sensor) via actual value with engine speed greater than 3500 rpm.
Test 1.3: Check reference signal of component B2/5 (Hot film mass air flow sensor).
Test 1.4: Check power supply of component B2/5 (Hot film mass air flow sensor).
1.1. Check signal of component B2/5 (Hot film mass air flow sensor) via actual value with engine OFF. Warning!Communication with ECU required.
1.2. Check signal of component B2/5 (Hot film mass air flow sensor) via actual value with engine speed greater than 3500 rpm. Warning!Communication with ECU required.
1.3. Check reference signal of component B2/5 (Hot film mass air flow sensor). Test sequence
- Switch on ignition. Status of relevant actual value: - HFM-SFI ( Reference signal ):Warning! Communication with ECU required. Specified value
- Reference signal[46...59] ms Question
- Is the measurement value OK?
YES The actual value is okay.End of test
NO The actual value is not o.k.Possible cause and remedy
- 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)
1.4. Check power supply of component B2/5 (Hot film mass air flow sensor). Image legends
- B2/5 (Hot film mass air flow sensor) - Connector (5-pin) Test prerequisite
- The actual value is not o.k.
2010 Mercedes Benz C 300 4MATIC (204.081) V6-3.0L (272.948) Copyright ? 2013, ALLDATA 10.52SS Page 2
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) 2 and (B2/5) 1 - Switch on ignition. Specified value
- Voltage[11.0...15.0] V Question
- Is the measurement value OK?
YES The actual value is okay.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
- N10/1f43 (Fuse 43) - Cable for voltage supply End of test
