In any car one of the main roles is playedcooling system. How to check the coolant temperature sensor, every motorist should know. At all injector and carburetor machines, temperature sensors are installed, but they have a slightly different function.
For example, on carburetor engines, a sensortemperature only allows you to display information about the current value of the parameter on the dashboard. But in the injector systems, one sensor allows not only to show the current system temperature on the instrument panel, but also sends a signal to the computer, which includes a cooling fan.
This device is needed in order to showthe temperature in the cooling system. As mentioned above, the ECU turns on the cooling fan installed on the radiator using this sensor.
In addition, by analyzing the data coming from the device, the microcontroller system allows to correct the crankshaft speed by XX (idle) during warm-up.
This changes the ratio of air and gasolinein the fuel mixture, the ignition angle is corrected. In the design of temperature sensors, which are used on cars, the properties of semiconductors are used. Such materials have different resistance to electric current when the ambient temperature changes.
But the sensors that are installed on thecarburetor engines and incorporating a cooling fan, are made of bimetallic plates. They simply deform upon reaching a certain temperature and switch power contacts.
You must know how the device works,Before checking the coolant temperature sensor. DETZH VAZ-2110 is installed directly in the thermostat housing. It has two outputs, one of which is connected to the housing and is closed to the ground, and the second goes to the microcontroller control unit.
From the microcontroller comes on the DCE voltage5 V. It goes further to the working element by means of a spring made of conductive material. The thermistor has a negative temperature coefficient, therefore, when the temperature in the cooling system rises, its resistance decreases.
By voltage difference by the electronic unitthe temperature is calculated. If the device fails, it must be checked, and in case of a breakage, it must be replaced by a new one. Repair or attempt to restore the device does not make sense, its cost is not very large.
But before you check the coolant temperature sensor VAZ-2109, you need to pay attention to the symptoms that may occur when this device breaks down:
The fan in the cooling system may not workalso due to a breakdown in the power system. Often, the relay, wires, and electric motor fail. Therefore, you need to make sure that the fan is in working order, to do this, replace the electromagnetic relay and connect the motor directly.
You need to know how to check the temperature sensorcoolant in "Passat B3", having at hand a minimum set of tools. You only need a multimeter. Among the main sensor failures are the following:
When the calibration is broken, the sensor startsshow "weather." As a result, the ECU uses incorrect information, corrects ignition and fuel injection inappropriately. As a result, the cold engine is quite difficult to start up, the consumption of gasoline increases, the cooling fan turns on spontaneously.
If there is a short circuit in the sensor, then the faultusually becomes the destruction or deformation of the shell. Such a breakdown is determined by the electronic control unit, it gives an error signal to the dashboard. The leakproofness of the sensor housing is also lost in case of mechanical damage, much less as a result of long operation, especially with running water in the cooling system.
In the event that there is no contact,The microcontroller puts the engine in emergency mode. At the same time, the cooling fan functions continuously to prevent the engine from overheating. If you can restore the contact in the wiring harness without problems, in the first three cases only the sensor replacement will help.
Before checking the temperature sensorcooling fluid VAZ-21099, it is necessary to find it on the engine. On domestic machines with front-wheel drive this device is located on the thermostat housing. In carburetor vehicles, the temperature sensor is installed in the engine block, also on the side of the thermostat, under the ignition distributor.
In other cars this device canTo be located both on exit branch pipes near a head of the block, and on the thermostat. On some vehicles, two sensors are used, one of which is necessary for the functioning of the temperature indicator located on the dashboard. And the second sensor sends a signal to the microcontroller ECU.
It is necessary to dismantle the device before checking the coolant temperature sensor on the VAZ-2107. To do this you need:
At the time of repair it is advisable to cover a hole with a clean rag. Verification is as follows:
Further, it is necessary to heat the water and check with the data given in the table.
Water temperature, ºС | Resistance of the sensor, Ohm |
-20 | 28680 |
0 | 9420 |
20 | 3520 |
40 | 1459 |
60 | 667 |
80 | 332 |
100 | 177 |
If all the indications are insignificant, thenthis can be attributed to the measurement error. But if the difference is significant, it is necessary to install a new sensor. And you can buy in any car store, the cost of these devices is relatively low. Installation is in the reverse order of dismantling.
Do not use when installing the sensor of a FSM tapeor silicone sealants. It is enough to install a new copper washer, which will ensure the proper level of tightness in the system. If you use sealants, they can get inside the system and the channels will clog. Clear the system from this kind of clog will be difficult, it may even have to completely disassemble the engine in parts to get rid of them.
