CPC Pressure Sensor: Inspection

WARNING: This page is about a different car, the 2022 Subaru WRX. However, it is still accessible from the selected car via links, so may be relevant.

Check that the CPC pressure sensor has no deformation, cracks or other damages.
Connect the dry-cell battery positive terminal to terminal No. 3 and the dry-cell battery negative terminal to terminal No. 1, and connect the circuit tester positive terminal to terminal No. 2 and the circuit tester negative terminal to terminal No. 1.
NOTE:
- Use new dry-cell batteries.
- Using a circuit tester, check that the initial voltage of each dry-cell battery is 1.6 V or more. And also check that the voltage of three batteries in series is between 4.8 - 5.2 V.
- For power supply, 5 V DC constant voltage power source can also be used.
Courtesy of SUBARU OF AMERICA, INC.

Check the voltage at a normal atmospheric pressure.

NOTE:

The atmospheric pressure at higher altitude is lower than normal. Therefore, the voltage is lower than the standard value.

Terminal No.	Standard
2 (+) - 1 (-)	Approx. 3.6 V (when 25°C (77°F))

Connect the Mighty Vac to the pressure port (A) of CPC pressure sensor.

Courtesy of SUBARU OF AMERICA, INC.

Check the voltage when generating vacuum using Mighty Vac.

CAUTION:

Do not apply a vacuum that exceeds -50 kPa (-0.5 kg/cm ² , -7.2 psi). Doing so may damage the CPC pressure sensor.

NOTE:

When vacuum occurs at the pressure port of CPC pressure sensor, the voltage will drop from the value as in step 3.

Pressure	Terminal No.	Standard
-50 kPa (-0.5 kg/cm² , -7.2 psi)	2 (+) - 1 (-)	Approx. 2 V (when 25°C (77°F))