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
- 8. Fuel system
   + 8.1.1. Introduction
   - 8.2. System of injection of petrol engines Principle of work of PMS Principle of work of HFM
      8.2.2. Self-diagnosing of a condition of system of ignition and injection of fuel
      8.2.3. Air flowmeter
      8.2.4. Thermal sensor of cooling liquid
      8.2.5. The sensor of the soaked-up air
      8.2.6. System of vacuum pipelines
      8.2.7. The fuel distributor with valvate nozzles
      8.2.8. Valvate nozzles
      8.2.9. Oxygen sensor (lambda probe)
      8.2.10. Diagnostics of malfunctions of system of injection of gasoline
      8.2.11. What should be known to the owner of the car with the injector engine
      8.2.12. Turbo doctor
   + 8.3. System of injection and power supply of diesel engines
   + 8.4. System of production of exhaust gases
+ 9. Transmission
+ 10. Running gear
+ 11. Steering
+ 12. Brake system
+ 13. Body
+ 14. Electric equipment
+ 14.2. Electrical circuitries

8.2.5. The sensor of the soaked-up air


The thermal sensor takes temperature of the soaked-up air. This size together with a signal of the sensor of pressure of the inlet gas pipeline (system of PMS management) serves as criterion for evaluation of amount of the let-in air. Tremodatchik of the soaked-up air is the NTC resistor (NTC – negative temperature coefficient) which resistance decreases at temperature increase.

The thermal sensor is located on the left side of a cross pipe of the air filter.


Remove the thermal sensor together with the shtekkerny socket, for this purpose squeeze both brackets (shooters).


1. Remove the shtekkerny socket.
2. Suspend the thermal sensor in a water bath and slowly heat it.
3. Check an ohmmeter thermal sensor resistance. The measured value is considered normal if it is in the admission of 5% (see the table Thermal Sensor Resistance).
4. If at measurements the thermal sensor does not reach preset values, it should be replaced.


1. Spread the shtekkerny socket of a wire.
2. Check a sealing ring of round section for absence of damage and porosity.
3. Insert the thermal sensor with a sealing ring. Squeeze out outside of a bracket until they are not recorded with click.

Thermal sensor resistance

+10 °C
apprx. 9670 Ohms
+20 °C
apprx. 6060 Ohms
+30 °C
apprx. 3900 Ohms
+40 °C
apprx. 2600 Ohms
+50 °C
apprx. 1760 Ohms
+60 °C
apprx. 1220 Ohms
+70 °C
apprx. 860 Ohms
+80 °C
apprx. 620 Ohms