Barometric Pressure Sensor Circuit Slow Response (Honda)
What does P1197 mean?
The P1197 code means the vehicle's onboard diagnostic system has detected: Barometric Pressure Sensor Circuit Slow Response (Honda). This is a low severity code.
Common Symptoms
- Check Engine Light on
- Slight loss of power at altitude
- Minor fuel economy decrease
- No significant drivability issues at sea level
- Possible mild rough idle
Probable Causes (Ranked by Likelihood)
- Faulty barometric pressure (BARO) sensor Very High
- Corroded BARO sensor connector High
- Wiring issue in BARO sensor circuit Moderate
- PCM internal BARO reading malfunction Moderate
- Vacuum reference hose blockage (if applicable) Low
Step-by-Step Diagnostic Procedure
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Read the BARO sensor value on a scan tool and compare to actual atmospheric pressure
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Inspect the BARO sensor connector for corrosion
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Test the sensor output voltage at different altitudes if possible
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Check wiring continuity between the sensor and PCM
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Replace the BARO sensor if readings do not match atmospheric pressure
Frequently Asked Questions
What does the barometric pressure sensor do?
The BARO sensor measures atmospheric pressure, which changes with altitude and weather. The ECM uses this data to adjust fuel delivery and ignition timing for optimal performance at any elevation.
Is P1197 more noticeable at high altitudes?
Yes. A slow-responding BARO sensor has the most impact at altitude because the ECM needs accurate pressure data to compensate for thinner air. At sea level, the effect is minimal.
Is the BARO sensor the same as the MAP sensor on Honda?
On some Honda models, the MAP sensor also functions as the BARO sensor when the engine is off or at key-on engine-off. On other models, it is a separate sensor. Check your specific model for details.