P0109 Fault Code

Manifold Absolute Pressure/Barometric Pressure Circuit Intermittent

• What does that mean?
• Symptoms
• Causes
• Solutions

The P0109 fault code indicates an intermittent issue with the Manifold Absolute Pressure (MAP) or Barometric Pressure (BARO) circuit. This code is set when the vehicle's engine control module (ECM) detects that the voltage signal from the MAP sensor deviates from expected values. The MAP sensor measures the pressure inside the intake manifold, providing critical data for the fuel injection and ignition timing. An intermittent fault can cause fluctuations in engine performance, leading to potential drivability issues.

What are the symptoms of the P0109 code?

• Engine stalling or poor idle quality
• Decreased engine performance
• Increased fuel consumption
• Check Engine Light illuminated on the dashboard
• Inconsistent power delivery during acceleration

What causes the P0109 code?

• Damaged wiring or connectors related to the MAP sensor
• Faulty MAP sensor
• Poor ground connection
• Vacuum leaks in the intake manifold
• Issues with the ECM or other related engine management systems

How to fix P0109?

• Inspect and repair any damaged wiring or connectors for the MAP sensor
• Replace the MAP sensor if it is faulty
• Check for vacuum leaks and repair as necessary
• Ensure proper grounding of the sensor circuit
• If all else fails, consider diagnosing the ECM for any internal faults