Barometric Pressure Sensor: Testing and Inspection

1997 Mazda Millenia V6-2.5L DOHCSECTION Testing and Inspection















EGR BOOST SENSOR
Inspection

NOTE: The following vacuum values are indicated by relative pressure from atmospheric pressure.

1. Connect the Special Service Tools (Engine Signal Monitor) to the PCM as shown.

CAUTION: Do not apply a vacuum outside of the specified limits. Doing so will damage the EGR boost sensor.

2. Apply vacuum to the EGR boost sensor according to the following procedure.
3. Increase the applied vacuum from 0 kPa (0 mm Hg, 0 in.Hg) to -81.3 kPa (-610 mmHg, -24.0 in.Hg) and verify that the PCM terminal 3F voltage decreases accordingly.

Reference data

NOTE: The output voltage varies with the measuring condition.

Measuring condition:
- Input voltage - 5.0 V

- Atmospheric pressure - 101.3 kPa (760 mmHg, 29.9 in.Hg)
- Outside temperature - 25°C (77°F)

4. If not as specified, perform the following inspection.
(1) Harness continuity.
- Between PCM terminal 3F and EGR boost sensor terminal A
- Between PCM terminal 3AB and EGR boost sensor terminal B
- Between PCM terminal 3Aand EGR boost sensor terminal C
(2) Terminal voltage (Ignition switch ON)
- EGR boost sensor terminal B voltage: Ground (Below 1.0 V)
- EGR boost sensor terminal C voltage: Constant voltage (4.5-5.5 V)
5. If terminal voltage is correct and if there is harness continuity, replace the EGR boost sensor.

RENDER: 1.0x

NO RELATED

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • You smell fuel, burning insulation, or see smoke.
  • Brakes feel soft, pull hard to one side, or make grinding noises.
  • The engine overheats, stalls repeatedly, or misfires under load.
  • You are missing required tools, torque specs, or safe lifting equipment.
  • You are not confident in the next step or safety outcome.