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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 >> Manufacturer Code Charts >> 2029

Manufacturer Code Charts: 2029


The value of component B2/5b1 (Intake air temperature sensor) is implausible. (P0111)


Possible cause:

- B11/4 (Coolant temperature sensor)
- B2/5 (Hot film mass air flow sensor)
Affected functions:

- Engine diagnosis

-------------------------------------------------

Test 1: Check component B2/5b1 (Intake air temperature sensor).

Test 2: Check component B11/4 (Coolant temperature sensor).

1. Check component B2/5b1 (Intake air temperature sensor).

Test 1.1: Check component B2/5b1 (Intake air temperature sensor) using actual value.

Test 1.2: Check plausibility of actual value B2/5b1 (Intake air temperature sensor) in control module ME 9.7.

Test 1.3: Check internal resistance of component B2/5b1 (Intake air temperature sensor).

1.1. Check component B2/5b1 (Intake air temperature sensor) using actual value.
Test prerequisites

- Switch off ignition.
- Leave vehicle with engine hood open for > 12 h.
Note

- The test prerequisites must be fulfilled for the test result to be meaningful.


Test sequence

- Switch on ignition.
Status of relevant actual value:
- Intake air temperature:Warning! Communication with ECU required.
- Ambient temperature:Warning! Communication with ECU required.
Specified value

- The intake air temperature may be max. 5° C below the ambient temperature or 15° C above the ambient temperature.
Question

- Is the actual value for intake air temperature OK?


YES
The actual value is okay.Further procedure

- If only fault codes 1599 and 1600 occur in control unit ME-SFI, erase the fault memory.
- The component may not be replaced.
End of test

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

- Check plausibility of actual value B2/5b1 (Intake air temperature sensor) in control module N3/10 (ME-SFI [ME] control unit).
- Check internal resistance of component B2/5b1 (Intake air temperature sensor).


1.2. Check plausibility of actual value B2/5b1 (Intake air temperature sensor) in control module ME 9.7.
Image legends

- Picture1
- B2/5 (Hot film mass air flow sensor)
- Connector (5-pin)
- Picture2
- B2/5 (Hot film mass air flow sensor)
- Connector (4-pin)
Test prerequisite

- The actual value is not o.k.
Test sequence

- Detach coupling at component B2/5 (Hot film mass air flow sensor).
- Switch on ignition.
Status of relevant actual value:
- Intake air temperature:Warning! Communication with ECU required.
Specified value

- If the connector is unplugged at component B2/5b1 (Intake air temperature sensor), value [ -40° C ] is displayed.
- Bridge pin 2 in pin 3 at the unplugged connection of component B2/5b1 (Intake air temperature sensor).The value is approx. [ 150° C ] for a short period of time and drops back down to the substitute value of approx. [ -40° C ].
Question

- Is the actual value o.k.?













YES
The actual value is okay.Further possible causes of fault

- Check internal resistance of component B2/5b1 (Intake air temperature sensor).


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

- Signal wire
End of test

1.3. Check internal resistance of component B2/5b1 (Intake air temperature sensor).
Test sequence

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

- Resistor(0° C): [5100...5900]ohms
- Resistor(5° C): [4100...4800]ohms
- Resistor(10° C): [3300...3900]ohms
- Resistor(15° C): [2700...3200]ohms
- Resistor(20° C): [2350...2500]ohms
- Resistor(25° C): [1900...2100]ohms
- Resistor(30° C): [1600...1700]ohms
- Resistor(35° C): [1300...1500]ohms
- Resistor(40° C): [1100...1200]ohms
- Resistor(45° C): [920...1100]ohms
- Resistor(50° C): [800...900]ohms
Question

- Are the measurement values OK?







YES
The measurement values are OK.End of test

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

- B2/5b1 (Intake air temperature sensor)
End of test

2. Check component B11/4 (Coolant temperature sensor).

Test 2.1: Check component B11/4 (Coolant temperature sensor) using actual value.

Test 2.2: Check signal lines on component B11/4 (Coolant temperature sensor).

Test 2.3: Check internal resistance of component B11/4 (Coolant temperature sensor).

2.1. Check component B11/4 (Coolant temperature sensor) using actual value.
Test prerequisite

- The actual value is not o.k.
Test sequence

- Switch on ignition.
Status of relevant actual value:
- Coolant temperature:Warning! Communication with ECU required.
- Coolant temperature sensor ( Signal voltage ):Warning! Communication with ECU required.
Specified values

- Voltage[20° C]: [3.45...3.32] V
- Voltage[30° C]: [2.93...2.82] V
- Voltage[40° C]: [2.41...2.32] V
- Voltage[50° C]: [1.93...1.86] V
- Voltage[60° C]: [1.51...1.46] V
- Voltage[70° C]: [1.18...1.13] V
- Voltage[80° C]: [0.90...0.87] V
- Voltage[90° C]: [0.70...0.67] V
- Voltage[100° C]: [0.54...0.25] V
- Voltage[110° C]: [0.42...0.40] V
Question

- Are the measurement values OK?


YES
The measurement values are OK.End of test

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

- Line from component B11/4 (Coolant temperature sensor) to component N3/10 (ME-SFI [ME] control unit)
- B11/4 (Coolant temperature sensor)
End of test

2.2. Check signal lines on component B11/4 (Coolant temperature sensor).
Test sequence

- Switch on ignition.
Status of relevant actual value:
- Coolant temperature sensor ( Signal voltage ):Warning! Communication with ECU required.
Specified value

- If the connection is unplugged at component B11/4 (Coolant temperature sensor), the value is approx. 5 V.
- Bridge pin 1 in pin 2 at the unplugged connection of component B11/4 (Coolant temperature sensor).The value is< 0.5 V.
Question

- Is the actual value o.k.?


YES
The actual value is okay.Further possible causes of fault

- Check internal resistance of component B11/4 (Coolant temperature sensor).


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

- Check lines from component B11/4 (Coolant temperature sensor) to component N3/10 (ME-SFI [ME] control unit).
End of test

2.3. Check internal resistance of component B11/4 (Coolant temperature sensor).
Test prerequisite

- The actual value is not o.k.
Test sequence

- Switch off ignition.
- Disconnect connector at component B11/4 (Coolant temperature sensor).
- Measure resistance with multimeter between pins ( B11/4 ) 1 and ( B11/4 ) 2
Specified values

- Resistor(20° C): [3030...3130]ohms
- Resistor(30° C]: [1950...2050]ohms
- Resistor(40° C): [1275...1375]ohms
- Resistor(50° C): [850...950]ohms
- Resistor(60° C): [600...650]ohms
- Resistor(70° C): [420...460]ohms
- Resistor(80° C): [305...335]ohms
- Resistor(90° C): [220...240]ohms
- Resistor(100° C): [160...180]ohms
- Resistor(110° C): [120...140]ohms
Question

- Are the measurement values OK?


YES
The measurement values are OK.End of test

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

- B11/4 (Coolant temperature sensor)
End of test

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