OBD-II code · Powertrain (generic)
P0109 Manifold Absolute Pressure / Barometric Pressure Circuit Intermittent
The ECU detects intermittent signal dropouts on the MAP/BARO sensor circuit. Fault is not constantly present — typically caused by loose connectors, chafed wiring, or a sensor failing under thermal load.
Is it safe to drive with P0109?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyMAP connector loose or corroded
- PossibleSensor fails when hot
- PossibleWiring chafed or pinched
Repair at a glance
- Difficulty
- Medium
- DIY friendly
- Often, with basic tools
- Typical labour
- 0.5–2 h
- Emissions test
- Likely to fail
- After the fix
- A drive cycle is needed before the light stays off
- Parts involved
- Map Sensor, Map Connector, Map Wiring
Related codes
- P0106Manifold Absolute Pressure Sensor Range/Performance
- P0107Manifold Absolute Pressure Sensor Low Input
- P0108Manifold Absolute Pressure Sensor High Input
- P010AMass or Volume Air Flow Sensor B Circuit
- P010BMass or Volume Air Flow Sensor B Circuit Range/Performance
- P010CMass or Volume Air Flow Sensor B Circuit Low
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.