What does it mean?
P1107 is a Powertrain (engine, transmission, fuel system) fault code. It indicates: BARO Pressure Sensor Circuit Low Input .
Symptoms
- Check engine light on with the barometric value stored at an implausibly low reading
- Rich or lean running because the module cannot correct fuelling for altitude
- Poor throttle response and reduced power, especially noticeable at higher altitude
- Hard starting and an unsettled idle
- Higher fuel consumption and possible black smoke
- Emissions test failure in some cases
Likely causes
- Signal wire shorted to ground where the loom is chafed or pinched
- Open or missing 5 V reference feed to the sensor, which collapses the signal
- Corroded or water-damaged connector at the sensor
- Internally shorted sensor element or a failed sensor circuit board
- Poor common ground shared with other sensors, pulling several readings low
- Damaged loom from a previous repair or an incorrectly pinned connector
- Module input fault as the last item to check
How to fix it
- Compare the live barometric value with the actual atmospheric pressure for the location; a value near zero confirms the low input
- Where the function is shared with the MAP sensor, compare barometric and manifold values with the ignition on and the engine stopped
- Unplug the sensor and check for 5 V on the reference pin with the ignition on; no reference sends the diagnosis upstream
- With the sensor disconnected, check the signal wire for a short to ground
- Voltage-drop test the sensor ground and clean the shared ground point if the drop is excessive
- Inspect the connector for moisture, corrosion and pushed-back terminals
- Repair the wiring or replace the sensor, then confirm the barometric value is realistic before returning the vehicle