P1105
HondaThe Engine Control Module (ECM) or Powertrain Control Module (PCM) has detected a voltage or signal input from the Barometric Pressure (BARO) sensor that is outside the specified operating range, indicating a circuit malfunction.
Medium SeverityThe P1105 code indicates an issue with the Barometric Pressure (BARO) sensor circuit in your Honda vehicle. This typically means the engine computer is receiving an implausible signal from the sensor, which can lead to incorrect fuel mixture calculations and affect engine performance.
⚠️ Before You Begin (Safety First)
Always ensure the engine is off and cool before working on any engine components. Disconnect the battery's negative terminal to prevent electrical shock or damage to the vehicle's electrical system before performing any inspections or repairs involving wiring or sensors. Be cautious of hot engine parts and rotating components.
Common Symptoms
- Check Engine Light (CEL) illumination
- Reduced engine performance
- Poor fuel economy
- Rough idle
- Engine hesitation or stalling
- Difficulty starting
Common Causes
- Faulty Barometric Pressure (BARO) sensor
- Damaged or corroded wiring in the BARO sensor circuit
- Loose or corroded electrical connectors at the BARO sensor or ECM/PCM
- Vacuum leaks affecting pressure readings
- Faulty Engine Control Module (ECM) or Powertrain Control Module (PCM) (rare)
Frequently reported on: Honda Civic (2001-2005), Honda Accord (1998-2002), Honda CR-V (1997-2001), Honda Odyssey (1999-2004), Honda S2000 (2000-2009)
Diagnostic Steps
- Connect an OBD-II scanner to confirm the P1105 code and check for any other related codes.
- Visually inspect the Barometric Pressure sensor and its electrical connector and wiring for any signs of damage, corrosion, or loose connections.
- Ensure the BARO sensor is properly seated and free from obstructions.
- If accessible, use a multimeter to check the voltage supply and signal output of the BARO sensor according to your vehicle's service manual specifications.
- Clear the code with an OBD-II scanner and test drive the vehicle to see if the code returns.
- If the sensor appears faulty after testing, consider replacing the BARO sensor with a new, OEM-quality part.
👨🔧 When to Call a Professional
If you have replaced the BARO sensor and thoroughly checked all associated wiring and connectors without resolving the P1105 code, it's time to consult a professional technician. This could indicate a deeper electrical issue within the ECM/PCM or a more complex wiring harness problem.
Commonly Asked Questions
What does the Barometric Pressure (BARO) sensor do?
The BARO sensor measures atmospheric pressure, which helps the engine computer adjust the air-fuel mixture for optimal performance based on altitude and weather conditions.
Can I drive with a P1105 code?
While you might be able to drive, it is not recommended for an extended period. The engine's performance, fuel economy, and emissions will likely be negatively affected, and ignoring it could lead to further engine issues.
Is the BARO sensor the same as the MAP sensor?
While both measure pressure, they are distinct. The BARO sensor measures atmospheric pressure, while the Manifold Absolute Pressure (MAP) sensor measures the pressure inside the engine's intake manifold. Some vehicles integrate these functions or use one predominantly. For P1105, it specifically points to the BARO circuit in Honda.
How can I test the BARO sensor?
You can typically test a BARO sensor by checking its voltage output with a multimeter, comparing it to manufacturer specifications at different atmospheric pressures. An OBD-II scanner capable of live data can also show the sensor's readings.
What is the average cost to replace a BARO sensor?
The cost of a new BARO sensor itself can range from $50 to $150. Labor costs for replacement are usually low, as it's often an accessible part, typically adding another $50-$100 if done by a mechanic.