OBD-II FAULT CODE
P0109
Manifold Absolute Pressure/Barometric Pressure Circuit Intermittent
Meaning, symptoms, likely causes, diagnostic checks and repair guidance for P0109.
- Check Engine light
- Poor drivability or reduced fuel economy depending on fault
- Faulty MAP sensor
- Vacuum hose leak/blockage
- Wiring/connector fault
- Loose connector
- Moisture/corrosion
- Scan all modules and record freeze-frame data before clearing codes
- Check battery voltage and related fuses
- Compare MAP reading key-on-engine-off to barometric pressure
- Inspect vacuum port/hose and wiring
- Wiggle-test harness while watching live data
- Clean blocked port, repair hose/wiring, replace sensor if confirmed faulty
- Clean/secure connector and repair damaged harness
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Disclaimer: Information is provided for general guidance only and may not apply to all vehicles. Always consult a qualified technician.