The absolute pressure sensor in the car, complete with a solenoid valve, is used to control the vacuum depth in the intake manifold. The change in pressure relative to barometric pressure is the result of a change in the current load on the engine. The sequence of operations when checking a pressure sensor depends on its specific type.
Necessary
- - vacuum manometer;
- - Vacuum pump;
- - tester (voltmeter);
- - tachometer.
Instructions
Step 1
To test an analog type sensor, first attach an adapter to the vacuum hose between the intake manifold and the sensor. Connect a vacuum gauge.
Step 2
Start the engine and let it idle. If the manifold vacuum is not too high, that is, it does not exceed 520 mm Hg. Art., check the vacuum hose for kinks and damage, as well as the correct installation of the camshaft drive belt. A defect in the sensor diaphragm can also be the cause of the low vacuum.
Step 3
Disconnect the vacuum gauge and connect a vacuum pump instead. Create a vacuum of about 555-560 mm Hg through the pump on the sensor. Art. Then stop pumping out with the vacuum pump. A working sensor will show a vacuum for at least 25-30 seconds.
Step 4
To test a digital type absolute pressure sensor, use a tester by switching to voltage measurement.
Step 5
Switch on the ignition. Locate the power and ground pins. Connect the positive lead of the voltmeter to the wire that is connected to the signal pin of the pressure sensor. A working device will show a voltage relative to mass about 2.5 V.
Step 6
Switch the device to tachometer mode. Disconnect the vacuum hose from the pressure sensor. Connect the positive terminal of the meter to the signal wire and the negative terminal to the ground wire of the pressure sensor. Normally, the device will show 4400-4850 rpm.
Step 7
Connect a vacuum pump to the sensor hose. Change the vacuum in the sensor with the pump, observing the readings of the device in tachometer mode. A sign of serviceability will be the stability of the vacuum and the readings of the device.
Step 8
Disconnect the vacuum pump. The device in tachometer mode should show from 4400 to 4900 rpm. If these values are not maintained, replace the sensor with a good one.
