Intake air temperature sensor
Content
Typical DTVV
Intake air temperature sensor is one of many systems and sensors in a car. a breakdown in its operation can directly affect the operation of the internal combustion engine, especially in the cold season.
What is an intake air sensor and where is it located
Intake air temperature sensor (abbreviated DTVV, or IAT in English) needed to adjust the composition of the fuel mixturesupplied to the internal combustion engine. This is necessary for the normal operation of the motor in different temperature conditions. Accordingly, an error in the intake air temperature sensor to the manifold threatens with excessive fuel consumption or unstable operation of the internal combustion engine.
DTVV is located on the air filter housing or behind it. It depends on the design of the car. He performed separately or may be part of the mass air flow sensor (DMRV).
Where is the intake air temperature sensor located?
intake air temperature sensor failure
There are several signs of a malfunctioning intake air temperature sensor. Among them:
- interruptions in the operation of the internal combustion engine at idle (especially in the cold season);
- too high or low idle speed of the internal combustion engine;
- problems with starting the internal combustion engine (in severe frosts);
- reduction in ICE power;
- fuel overrun.
Breakdowns can be due to the following reasons:
- mechanical damage to the sensor caused by solid particles;
- loss of sensitivity due to pollution (increase in the inertia of transients);
- insufficient voltage in the vehicle's electrical system or poor electrical contacts;
- failure of the signal wiring of the sensor or its incorrect operation;
- short circuit inside IAT;
- contamination of the sensor contacts.
Checking and cleaning DTVV.
Checking the intake air temperature sensor
Before you check the intake air temperature sensor, you need to understand the principle of its operation. The sensor is based on a thermistor. Depending on the temperature of the incoming air, DTVV changes its electrical resistance. The signals generated in this case are sent to the ECM in order to obtain the correct fuel mixture ratio.
Diagnosis of the intake air temperature sensor must be performed on the basis of measuring the resistance and the magnitude of the electrical signals emanating from it.
The test begins with the calculation of the resistance. To do this, use an ohmmeter by removing the sensor from the car. The procedure occurs by disconnecting two wires and connecting them to a measuring device (multimeter). The measurement is carried out in two modes of operation of the internal combustion engine — “cold” and at full speed.
Supply voltage measurement
Sensor resistance measurement
In the first case, the resistance will be high-resistance (several kOhm). In the second - low-resistance (up to one kOhm). The operating instructions for the sensor must have a table or graph with resistance values \uXNUMXb\uXNUMXbdepending on temperature. Significant deviations indicate incorrect operation of the device.
As an example, we give a table of the ratio of temperature and resistance of the intake air sensor for the internal combustion engine of the VAZ 2170 Lada Priora car:
| Intake air temperature, °C | Resistance, kOhm |
| -40 | 39,2 |
| -30 | 23 |
| -20 | 13,9 |
| -10 | 8,6 |
| 0 | 5,5 |
| +10 | 3,6 |
| +20 | 2,4 |
| +30 | 1,7 |
| +40 | 1,2 |
| +50 | 0,84 |
| +60 | 0,6 |
| +70 | 0,45 |
| +80 | 0,34 |
| +90 | 0,26 |
| +100 | 0,2 |
| +110 | 0,16 |
| +120 | 0,13 |
At the next stage, check the connection of conductors to the control device. That is, using a tester, make sure that there is conductivity of each contact to ground. Use an ohmmeter, which is connected between the temperature sensor connector and the disconnected control device connector. In this case, the value must be 0 ohm (note that you need a pinout for this). Check any contact on the sensor connector with an ohmmeter with the connector disconnected against ground.
DTVV resistance measurement for Toyota Camry XV20
For example, in order to check the resistance of the sensor on a Toyota Camry XV20 car with a 6-cylinder engine, you need to connect an ohmmeter (multimeter) to the 4th and 5th sensor outputs (see figure).
However, most often DTVV has two thermistor outputs, between which it is necessary to check the resistance of the element. we also bring to your attention the IAT connection diagram in the Hyundai Matrix car:
Connection diagram for DTVV with DBP for Hyundai Matrix
The final stage of verification is find out the voltage at the connector. In this case, you need to turn on the ignition of the car. The value of the electrical signal should be 5 V (for some DTVV models, this value may differ, check it in the passport data).
The intake air temperature sensor is a semiconductor device. As a result, it cannot be configured. It is only possible to clean the contacts, check the signal wires, as well as completely replace the device.
Intake air temperature sensor repair
How can I repair the temperature sensor BB.
Most the simplest type of IAT repair — cleaning. To do this, you will need some kind of cleaning fluid (carb cleaner, alcohol, or other cleaner). However, remember that you need to work carefully, in order to do not damage external contacts.
If you encounter a problem where the sensor shows the wrong temperature, instead of a complete replacement, you can repair it. For this buy a thermistor with the same or similar characteristicswhich has a thermistor already installed on the car.
The essence of the repair is soldering and replacing them in the sensor housing. To do this, you will need a soldering iron and the appropriate skills. The benefit of this repair is significant money savings, as the thermistor costs about a dollar or less.
Replacing the intake air temperature sensor
The replacement procedure is not difficult and does not take much time. The sensor is mounted on 1-4 bolts that need to be unscrewed, as well as a simple movement to disconnect the power connector in order to remove the intake air sensor from its place.
When buying a new sensor, make sure that it is suitable for your car. Its price ranges from $30 to $60, depending on the brand of car and manufacturer.
