Skoda Felicia

since 1994 release

Repair and operation of the car



Skoda Felicia
+ Cars of the Skoda Felicia brand
+ Maintenance instruction
+ Routine maintenance
+ Repair of the engine
- Cooling systems, heating
   General information and precautionary measures
   Detachment and replacement of hoses of the cooling system
   Removal, check of a state and installation of a radiator
   Removal, check of serviceability of functioning and installation of the thermostat
   Check of serviceability of functioning, removal, installation, dismantling and assembly of the fan of the cooling system
   Check of serviceability of functioning, removal and installation of electric switches and sensors of the cooling system
   Removal, installation, dismantling and assembly of the water pump
   System of heating/ventilation of salon - the general information
   Removal and installation of components of system of heating/ventilation of salon
   The air conditioning system - the general information and precautionary measures
   Removal and installation of components of the air conditioning system
+ Power supply system
+ Engine electric equipment
+ Coupling
+ Transmission
+ Power shafts
+ Brake system
+ Suspension bracket and steering
+ Body and finishing of salon
+ Onboard electric equipment





Check of serviceability of functioning, removal and installation of electric switches and sensors of the cooling system

Thermosensitive sensor switch of the fan of the cooling system

General information


The thermosensitive sensor switch carries out turning on of the fan on reaching temperature of cooling liquid of value 95 ÷ 99 of °C. Disconnection of contacts of the sensor switch happens at decrease in temperature to value not below 88 °C.

The sensor switch is screwed in the right side capacity of a radiator. Tightness of connection is reached by installation aluminum sealing washers. The top part of the case of the sensor switch is equipped with lyska under a wrench on 27 mm.

On the case of the sensor switch there are two conclusions for connection of an electrical wiring. Food on the sensor moves only at the included ignition. Protection of a chain is provided with a safety lock No. 4 (15 A).

CHECK

 PERFORMANCE ORDER

The detailed description of check of the sensor switch is provided in the Section Check of Serviceability of Functioning, removal, installation, dismantling and assembly of the fan of the cooling system among procedures of check of the fan.

REMOVAL

 PERFORMANCE ORDER

Before starting removal of the sensor switch, wait for full cooling of the engine and a radiator.

1. The sensor switch is screwed in a radiator body.
2. Disconnect a negative wire from the battery, then merge cooling liquid, having lowered its level lower than the level of an arrangement of the sensor switch. Alternatively, prepare a suitable stopper which can muffle quickly an opening under installation of the sensor switch. Try not to damage a radiator and not to allow hit in system of garbage and foreign objects.

3. Disconnect an electrical wiring from the sensor switch.

4. Carefully turn out the sensor switch and remove it from a radiator. Remove also sealing washer. If cooling liquid did not merge, immediately muffle an opening the prepared stopper.

INSTALLATION

 PERFORMANCE ORDER

1. Installation is made upside-down. Do not forget to replace a sealing washer. Tighten the sensor switch with the required effort, then add necessary amount of cooling liquid in system.
2. In conclusion start the engine and warm up it up to the normal working temperature. make sure of serviceability of functioning of the fan - it has to join and be switched off in due time.


Sensor of temperature of cooling liquid (CTS)

CHECK

 PERFORMANCE ORDER

1. On the petrol CTS models it is established in a thermostat casing in the left part of a head of cylinders.

2. On diesel models the sensor is in an output branch pipe of a cooling path in a forward part of a head.

On models of 1.3 l equipped with system of the central injection (SPFI), the sensor is connected only with temperature measuring instrument. on all other CTS models serves also for determination of temperature of systems of injection of fuel (petrol engines) or preheat (diesel engines).

3. The stabilized supply voltage on temperature measuring instrument from an instrument guard (via the switch of ignition and a safety lock). The condition of a contour of grounding of the measuring instrument is controlled by the CTS sensor. The main CTS component is the thermistor - the resistor which resistance falls with increase in temperature. At cold cooling liquid resistance of a thermistor is big and through the measuring instrument there passes small current, at the same time the arrow of the index is in the lower range of a scale (the blue sector). In process of an engine warming up resistance of the sensor falls, current grows and the arrow is displaced aside up, approaching the red sector of a scale. Faulty CTS is subject to replacement.
4. In case of refusal CTS first of all should check serviceability of functioning of other components of a combination of devices - if they are deenergized at all, check existence of food on a guard. If indications of measuring instruments are unstable, is faulty there can to be a voltage stabilizer which is built in in the printed circuit board of an instrument guard which needs to be replaced (see the Head Onboard electric equipment). If the failure only of temperature measuring instrument takes place, execute the checks stated in the following paragraphs.
5. If the arrow of the measuring instrument remains within the blue sector of a scale at the heated-up engine, disconnect an electrical wiring from CTS and ground the corresponding wire on the mass of a head of cylinders. If at inclusion of ignition of the shooter deviates, the sensor is faulty and is subject to replacement. If no changes in behavior of the measuring instrument happen, remove a combination of devices (see the Head Onboard electric equipment) and check for existence of conductivity on the site of a chain between the sensor and the measuring instrument. If conductivity takes place, therefore, the measuring instrument is faulty and is subject to replacement.
6. If the arrow of the measuring instrument constantly is in the red range of a scale, without reacting to cooling of the engine in any way, disconnect an electrical wiring from the sensor. If the arrow returns to the beginning of a scale at inclusion of ignition, it is necessary to replace CTS. Otherwise check the chain rest.

REMOVAL

 PERFORMANCE ORDER

Before starting CTS removal, wait for full cooling of the engine and a radiator.

1. Partially merge cooling liquid (lower than the level of an arrangement of CTS), or prepare a suitable cap.

2. Disconnect an electrical wiring from CTS. Now it is necessary to define type of the sensor installed on your car. The sensor can have as free, or carving landing.

3. The sensor supplied with a carving just is turned out from the engine. Do not forget to remove a sealing washer.

4. The sensor of free landing is fixed by a special clip which should be taken previously.

5. Then the sensor is just taken from the nest.

6. In conclusion also remove a sealing ring.

INSTALLATION

 PERFORMANCE ORDER

1. On the sensor with screw landing replace a sealing washer, then screw the sensor on the regular place and strongly tighten it.
2. In case of the sensor with free landing establish on it a new sealing ring, then push assembly in a landing nest and record it a clip.
3. Connect an electrical wiring, then add necessary amount of cooling liquid in system.


Sensor of temperature of system of injection of fuel (petrol models)

CHECK

 PERFORMANCE ORDER

1. On models of 1.3 l with the central injection of fuel (SPFI) the sensor of temperature is screwed in in a back part of the inlet pipeline. On all other engines the sensor is combined with CTS and installed in a thermostat casing on the left end of a head of cylinders.

2. The sensor represents a thermistor. The electronic control unit (ECU) of a control system of engine/injection of fuel gives supply voltage on the sensor and measures current, the sensor proceeding in a working chain which size is defined by thermistor temperature. The obtained information is used then among other entrance signals when determining the moment and duration of operation of injectors, installation of turns of idling, etc.
3. At violation of serviceability of functioning of a chain of the ECU sensor begins to ignore the signal developed by a thermistor, using instead of it the certain effective average value providing adequate functioning of under control systems. At the same time on an instrument guard the control lamp warning the owner of the vehicle about need of the address on car repair shop joins. Check of a condition actually of the sensor is possible only with use of the branded diagnostic reader of the Skoda company. In order to avoid risk of inactivation of ECU it is not necessary to make attempts to understand a situation by means of any other make-shifts.

Sensor of temperature of system of preheat (diesel models)

CHECK

 PERFORMANCE ORDER

The detailed description of the procedure of check of serviceability of functioning of system of preheat of the diesel engine is provided in the Part System of preheat of diesel engines of the Head Elektrooborudovaniye of the engine.

REMOVAL AND INSTALLATION

 PERFORMANCE ORDER

The sensor is united in the uniform block with CTS and is installed in the final branch pipe of a cooling path located in a forward part of a head of cylinders. The description of procedures of removal and installation of the sensor is given above.