Fuel and emission control systems

Barometric pressure (baro) sensor inspection

~2min read
Note
  • Perform the following inspection only when directed.
  • The following vacuum values are indicated by relative pressure from the barometric pressure sensor.
1. Connect the SSTs

(WDS or equivalent) to the DLC-2.

2. Turn the ignition switch to ON.

3. Select BARO on the SSTs

(WDS or equivalent).

4. Verify that the BARO PID (pressure) and barometric pressure are practically equal.

  • If not as verified, perform the Circuit Open/Short Inspection.

- If there is no open or short circuit, replace the barometric pressure sensor.

  • If as verified, go to next step.
5. Apply vacuum of -25.0 kPa {-187 mmHg, -7.38 inHg} to the barometric pressure sensor, and verify that the BARO variation from that of Step 4 is approx. 25.0 kPa {187 mmHg, 7.38 inHg}.
  • If not as verified, perform the Circuit Open/Short inspection.

- If there is no open or short circuit, replace the barometric pressure sensor.

Circuit Open/Short Inspection

1. Disconnect the PCM connector. (See PCM REMOVAL/INSTALLATION.)


2. Inspect the following wiring harness for open or short. (Continuity check)

Open circuit
  • If there is no continuity, the circuit is open. Repair or replace the harness.

- Barometric pressure sensor terminal A (harness-side) and PCM terminal 1G

- Barometric pressure sensor terminal B (harness-side) and PCM terminal 2H

- Barometric pressure sensor terminal C (harness-side) and PCM terminal 2K

Short circuit
  • If there is continuity, the circuit is shorted. Repair or replace the harness.

- Barometric pressure sensor terminal C (harness-side) and power supply.

- Barometric pressure sensor terminal C (harness-side) and body GND.

- Barometric pressure sensor terminal A (harness-side) and power supply.

- Barometric pressure sensor terminal A (harness-side) and body GND

Test yourself

A quick Mazda 6 quiz: every answer comes with an explanation and a link to the manual page.