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Home >> Mercedes Benz >> 2008 >> SLK 280 (171.454) V6-3.0L (272.942) >> Repair and Diagnosis >> A L L Diagnostic Trouble Codes ( DTC ) >> Testing and Inspection >> P Code Charts >> P0101 >> The measured air mass is implausible compared to the position of the throttle valve. (P0101)

The measured air mass is implausible compared to the position of the throttle valve. (P0101)


The measured air mass is implausible compared to the position of the throttle valve. (P0101)


Possible cause:

- B2/5 (Hot film mass air flow sensor)
- M16/6 (Throttle valve actuator)
Affected functions:

- Engine diagnosis
- Engine output

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

Test 2: Check component M16/6 (Throttle valve actuator).

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.
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

2. Check component M16/6 (Throttle valve actuator).

Test 2.1: Check component M16/6 (Throttle valve actuator) using actual value.

Test 2.2: Check component M16/6m1 (Actuator motor) by means of actuation.

Test 2.3: Check internal resistance of component M16/6m1 (Actuator motor).

Test 2.4: Check internal resistance of component M16/6 (Throttle valve actuator).

Test 2.5: Test voltage supply of the potentiometers of component M16/6 (Throttle valve actuator).

2.1. Check component M16/6 (Throttle valve actuator) using actual value.
Warning!Communication with ECU required.


2.2. Check component M16/6m1 (Actuator motor) by means of actuation.
Test prerequisite

- Operate engine at idling speed.
Note

- If the throttle valve angle is< 1,1°, unmetered air may be present.
Status of relevant actual value:
- Throttle valve angle:Warning! Communication with ECU required.
Move on to actuation with button F2

2.3. Check internal resistance of component M16/6m1 (Actuator motor).
Figure legend

- A -ConnectionTest cable 35-pin socket box
- 001 -Sockets of component N3/10 (ME-SFI [ME] control unit)
- 05 -35-pin socket box
- 050 -126-pin socket box
- 108 -Test cable 266 589 01 63 00
- N3/10 (ME-SFI [ME] control unit)
- II 1-63ConnectionTest cable
- III 64-126ConnectionTest cable
Warning!

- Connection A of test cable 108 may NOT be connected to connection B of the 126-pin socket box (050).
Continue to test with button F2







Test sequence

- Switch off ignition.
- Disconnect coupling M at component N3/10 (ME-SFI [ME] control unit).
- Measure resistance with multimeter between sockets (M.75) 75 and (M.74) 74 of the 126-pole socket box tester.
Specified value

- Resistor[1...10]ohms
Question

- Is the measurement value OK?


YES
The measurement value is OK.End of test

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

- Lines between N3/10 (ME-SFI [ME] control unit) and M16/6m1 (Actuator motor)
- M16/6m1 (Actuator motor)
End of test

2.4. Check internal resistance of component M16/6 (Throttle valve actuator).
Figure legend

- A -ConnectionTest cable 35-pin socket box
- 001 -Sockets of component N3/10 (ME-SFI [ME] control unit)
- 05 -35-pin socket box
- 050 -126-pin socket box
- 108 -Test cable 266 589 01 63 00
- N3/10 (ME-SFI [ME] control unit)
- II 1-63ConnectionTest cable
- III 64-126ConnectionTest cable
Warning!

- Connection A of test cable 108 may NOT be connected to connection B of the 126-pin socket box (050).
Continue to test with button F2







Test prerequisites

- The throttle flap of component M16/6 (Throttle valve actuator) should operate freely and must not stick or rub.
- At least one of the relevant actual values is not okay.
Test sequence

- Switch off ignition.
- Remove component B2/5 (Hot film mass air flow sensor).
- Disconnect coupling M at component N3/10 (ME-SFI [ME] control unit).
M16/6r3 (Actual value potentiometer (sliding contact 1))

- Measure resistance with multimeter between sockets (M.88) 88 and (M.43) 43 of the 126-pole socket box tester.
- Slowly operate throttle flap by hand up to full load.
Specified values

- Throttle valve not actuated[ca. 1380]ohms
- Throttle valve fully actuated[ca. 480]ohms
M16/6r4 (Actual value potentiometer (sliding contact 2))

- Measure resistance with multimeter between sockets (M.64) 64 and (M.43) 43 of the 126-pole socket box tester.
- Slowly operate throttle flap by hand up to full load.
Specified values

- Throttle valve not actuated[ca. 650]ohms
- Throttle valve fully actuated[ca. 1490]ohms
Question

- Are the measurement values OK?


YES
The measurement values are OK.Further possible causes of fault

- Test voltage supply of the potentiometers of component M16/6 (Throttle valve actuator).


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

- Lines to component M16/6 (Throttle valve actuator)
- M16/6 (Throttle valve actuator)
End of test

2.5. Test voltage supply of the potentiometers of component M16/6 (Throttle valve actuator).
Test prerequisite

- At least one of the relevant actual values is not okay.
- The power supply of component N3/10 (ME-SFI [ME] control unit) is OK.
Test sequence

- Switch off ignition.
- Connect socket box (126-pin) to component N3/10 (ME-SFI [ME] control unit).
- Measure direct voltage with multimeter between sockets (M.39) 39 and (M.43) 43 of the 35-pole socket box tester.
- Switch on ignition.
Specified value

- Voltage[4.75...5.25] V
Question

- Is the measurement value OK?


YES
The measurement value is OK.Possible cause and remedy

- Check lines from component M16/6 (Throttle valve actuator) to component N3/10 (ME-SFI [ME] control unit).
End of test

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

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

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