P0109: Manifold absolute pressure circuit intermittent
Drive carefully. Get it checked within a week or two.
Can I drive with P0109?
Yes, but drive carefully and get it checked soon. Loose connections or broken wires cause erratic vacuum readings while driving.
What does P0109 mean?
P0109 stands for Manifold Absolute Pressure/Barometric Pressure Circuit Intermittent.
Symptoms you may notice
- Engine hesitates or jerks when stepping on the gas
- Rough, unsteady idle at stoplights
- Reduced engine power and delayed gear shifts
How much does it cost to fix?
Repair costs for code P0109 depend on the specific underlying root cause, ranging from simple DIY checks to component replacement. The table below lists the most common causes and rough price ranges in USD:
- Loose MAP sensor electrical connector
- Chafed or fractured wiring strands inside insulation
- Intermittent internal sensor failure
- Loose ground connection on engine block
What to do next
- Inspect the harness clip to confirm it locks tightly onto the sensor.
- Perform a gentle harness wiggle test with the engine running.
- Check battery ground straps and engine block ground terminals.
Last updated: October 2026
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General guidance only, not a professional diagnosis. If the check-engine light is flashing, or the car is running rough, overheating or losing power, stop driving and get help.
About this code
Intermittent MAP sensor faults like P0109 occur during engine movement under load. A broken wire inside the harness or a loose locking tab on the plastic connector allows the signal to flicker, causing sudden stumbling. Thorough harness inspection is the key to solving it.