Note: To test the air conditioning system, you will need a dual temperature gauge.
1. Check the functionality of the measuring device (see the operating instructions supplied with the device).
2. Set the device to the°C mode.
3. Set the sensitivity of the device to 0.1°C.
4. Set the reading mode to (ΔT) = (T1 - T2).
5. Check two sensors T1 and T2 to correct the error value in determining (Δ) subtraction (T1-T2). Under the same conditions, both sensors should display the same value. To check, match the ends of the two sensors until they touch, then place the sensors in the air deflector on the dashboard. Set the maximum interior ventilation speed and wait until the displayed value stabilizes. Record error value (Δ).
Note: The engine does not need to be started.
Attention: Note the error value only after the temperature reading has stabilized. Calculate error value (Δ) = - (T1 - T2), which will need to be added to the value (ΔT).
Examples:
If (T1 - T2) = - 0.3°С, corrected value (ΔT) By (Δ) = +0.3°С
If (T1 - T2) = + 0.3 C, corrected value (ΔT) By (Δ) = -0.3°C
6. Place the car in a shaded area so that the air temperature is approximately 15°C.
7. Close the hood.
8. Open the front windows of the car.
9. Start the engine at idle.
10.Set the air conditioning controls to the following positions:
- air intake switch to outdoor air intake position;
- air distribution switch to mode "in face";
- temperature switch to the maximum cooling position;
- cabin fan speed switch to maximum speed mode (turn off if there is a rear control panel);
- set the doors of the front side and central deflectors to a neutral position;
- the air conditioner must be on (indicator light should be on).
Note: Before starting measurements, wait 5 minutes with the engine running at idle.
11. Measure the air temperature at the air intake grille (T3):
- Open the hood to gain access to the air intake grille.
- Insert the sensor into the hole in the air intake grille.
- Wait until the displayed value stabilizes.
- Record temperature value (T3).
- Close the hood.
12. Measure the air temperature on the left (T1) and law (T2) air deflectors by inserting sensor T1 into the left (1), and T2 sensor to the right (2) air deflectors.
13. After the temperature values have stabilized, determine the value (ΔT) between T3 and the greater of T1 or T2, (TK - maximum value). Write down the received value.
14. Determine value (ΔT) between T1 and T2 (count value (ΔT) from the display in mode (T1-T2)). Write received value (ΔT) subject to adjustment by the error value (Δ), obtained earlier.
15. If measurement (ΔT) = (T1-T2) unstable, do the following:
Note: Depending on the programming version of the air conditioning system of a particular vehicle, this test method may not be suitable, since the engine cooling fan may be activated, as a result of which the calculation of the value (ΔT) may be unstable. To eliminate this error, it is necessary to activate the radiator fan for the entire period during which T1 and T2 measurements will be made.
- stabilize the engine crankshaft speed at 2000 rpm for the time of temperature measurement T1 and T2;
- make sure that the cooling fan is activated;
- measure the temperatures T1 and T2.
16. Verify that the following conditions are met:
- the difference between T3 and the larger of the two T1 or T2 values must be greater than or equal to 5°C;
- the difference between T1 and T2 must be less than or equal to 2°C.
Note: If either of these conditions is not met, the air conditioning system will not work properly. It is necessary to identify and eliminate the cause of the malfunction.