Manifold Pressure/Vacuum Sensor: Testing and Inspection

Manifold Differential Pressure (MDP) Sensor Inspection
1. Disconnect manifold differential pressure sensor coupler.
2. Remove manifold differential pressure sensor (1).




3. Check pressure passage and air vent hole for clog. Clean if clogged.

CAUTION: Do not put drills or wires into passage and hole for cleaning. It causes damage in it.

4. Arrange 3 new 1.5 V batteries (2) in series and connect its positive terminal to "Vin" terminal of coupler and negative terminal to "Ground" terminal. Then check voltage between Vout" and "Ground".

Also, check if voltage reduces when vacuum is slowly applied up to 400 mmHg by using vacuum pump (3).

If check result is not satisfactory, replace manifold differential pressure sensor.

CAUTION: As connection to wrong terminal will cause damage to manifold differential pressure sensor, make absolutely sure to connect properly as shown in the figure.

Output voltage at "Vout" (When voltage at "Vin" is 4.5 V)
Applied 200 mmHg vacuum: 2.40 - 4.40 V
Applied 250 mmHg vacuum: 2.13 - 4.13 V
Applied 300 mmHg vacuum: 1.86 - 3.86 V
Applied 350 mmHg vacuum: 1.59 - 3.59 V
Applied 400 mmHg vacuum: 1.32 - 3.32 V




5. Install manifold differential pressure sensor. Connect manifold differential pressure sensor coupler securely.