2010 Mercedes Benz C 300 (204.054) V6-3.0L (272.947) Page 997

- 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锟斤拷 C): [3030...3130]ohms

- Resistor(30锟斤拷 C]: [1950...2050]ohms

- Resistor(40锟斤拷 C): [1275...1375]ohms

- Resistor(50锟斤拷 C): [850...950]ohms

- Resistor(60锟斤拷 C): [600...650]ohms

- Resistor(70锟斤拷 C): [420...460]ohms

- Resistor(80锟斤拷 C): [305...335]ohms

- Resistor(90锟斤拷 C): [220...240]ohms

- Resistor(100锟斤拷 C): [160...180]ohms

- Resistor(110锟斤拷 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

3. Check component Y110 (Three-disk thermostat valve).

Test 3.1: Component Y110 (Three-disk thermostat valve) is mechanically damaged or it sticks.