Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Barometric Pressure (BARO) Sensor
The BARO sensor measures barometric pressure to estimate the exhaust back pressure.
For vehicles with a turbocharger intake pressure and temperature (TCIPT) sensor, and without a BARO sensor, the BARO value is calculated from the TCIPT sensor value at key ON, engine OFF (KOEO). While driving, the BARO value is calculated from the TCIPT sensor value, with the difference calculated by the pressure drop across the air filter.
For direct injection vehicles, a BARO sensor is mounted internally to the PCM. The BARO sensor measures the barometric pressure to estimate the exhaust back pressure.
For vehicles without a BARO sensor and with a MAP sensor, the BARO value is inferred by the PCM based on the MAP value under certain operating conditions. At, or near wide open throttle the BARO value is calculated to be slightly higher than the MAP value, with the difference calculated by the pressure drop across the throttle plate.
For all other vehicles without a BARO sensor, the BARO value is inferred by the PCM. At, or near wide open throttle, the BARO value is calculated to be slightly higher than the inferred MAP value, with the difference calculated by the pressure drop across the throttle plate.
NO RELATED
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Affiliate disclosure: We may earn a commission at no extra cost to you.
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.