Mercedes of the S-class W202

1993-2000 of release

Repair and operation of the car

Mercedes W202
+ 1.2. General information
+ 2. Maintenance
+ 3. Engines
+ 4. Lubrication system
+ 5. Cooling system
+ 6. Heating, ventilation
- 7. System of ignition
   7.2. Safety measures at repair of electronic system of ignition
   7.3. Ignition coils
   + 7.4. Spark plugs
   - 7.5. Device of a preliminary warming up of the diesel
      - 7.5.1. Check of the device of a preliminary warming up Glow lamp Anchor Glow plugs Temperature sensor of cooling liquid The thermal sensor of the soaked-up air
      7.5.2. Self-diagnostics of the device
+ 8. Fuel system
+ 9. Transmission
+ 10. Running gear
+ 11. Steering
+ 12. Brake system
+ 13. Body
+ 14. Electric equipment
+ 14.2. Electrical circuitries Temperature sensor of cooling liquid


The temperature sensor takes temperature to cooling liquid and transmits the corresponding signals to the actuation device. The sensor contains a NTC element (NTC – negative temperature coefficient) which reduces the resistance with temperature increase. At the faulty sensor the actuation device gives reserve size. It leads to the fact that duration of a preliminary and subsequent warming up is incorrectly maintained.
1. Engine of 2,0 l: remove the 6-shtyrkovy plug from the relay of management of a warming up and measure resistance between a counter 6 on the plug and the case (the block of cylinders of the engine). If resistance strives for infinity, in the conducting line break. If resistance is below 1 Ohm, then in the electric line short circuit.
Preset value:
at a temperature of 25 °C: 2442 Ohms + 170 Ohms
at a temperature of 80 °C: 291 Ohm + 16 Ohms.
2. L engine 2,2 / 2,5: reduce pressure of cooling liquid. For this purpose uncover the compensation tank filled with cooling liquid.
3. Disconnect the plug (In 11/4) and unscrew the thermal sensor of cooling liquid.
4. Disconnect the plug (In 11/8х1) and unscrew "the thermal sensor of cooling liquid for the subsequent warming up" on a head of the block of cylinders.


1. Suspend the thermal sensor in a water bath and slowly heat it.
2. Check an ohmmeter thermal sensor resistance. The measured size as it should be if it is in admission limits + 5% (see the table Thermal Sensor Resistance).
3. If at measurements the thermal sensor does not reach preset values, then it should be replaced.


1. Screw in the thermal sensor with m 20 N.' moment.
2. Spread the cable plug (socket).
3. Fill in cooling liquid.
4. Warm up the engine and check the level of cooling liquid.

Thermal sensor resistance

20 °C
2500 Ohm
30 °C
1700 Ohm
40 °C
1170 Ohm
50 °C
830 Ohm
60 °C
600 Ohm
70 °C
435 Ohm
80 °C
325 Ohm
90 °C
245 Ohm
100 °C
185 Ohm