Faulty MAP or barometric pressure sensor giving a low or flat signal; Damaged, chafed or corroded wiring, or a poor connector at the sensor, causing a short to earth or open circuit on the signal wire; Missing or poor 5 volt reference supply to the sensor; Poor or open earth return from the sensor to the control unit; Blocked, split or disconnected vacuum hose to the sensor, where the sensor is remote-mounted; Fault inside the engine control unit.

P0107

Manifold Absolute Pressure/Barometric Pressure Sensor Circuit Low.

Generic
Powertrain
Generic code
Medium severity

How this code is built

P: SystemPowertrain
0: Defined bySAE, the same on every car
1: AreaFuel and air metering
07: FaultThe specific fault in that area

What it means

P0107 means the engine control unit has detected the signal voltage from the manifold absolute pressure (MAP) sensor, or the barometric pressure sensor circuit, is lower than expected. The control unit sees a voltage near zero or below the normal working range, which suggests very low pressure or an electrical fault such as a short to earth, open circuit or poor supply. The exact thresholds and which sensor is monitored vary by manufacturer and engine.

Symptoms

Engine warning light on
Poor or hesitant acceleration
Rough idle or stalling
Hard starting, especially when hot
Black smoke or a rich running condition
Higher than normal fuel consumption
Car may enter limp mode with reduced power

Possible causes

Faulty MAP or barometric pressure sensor giving a low or flat signallikely
Damaged, chafed or corroded wiring, or a poor connector at the sensor, causing a short to earth or open circuit on the signal wirelikely
Missing or poor 5 volt reference supply to the sensorpossible
Poor or open earth return from the sensor to the control unitpossible
Blocked, split or disconnected vacuum hose to the sensor, where the sensor is remote-mountedpossible
Fault inside the engine control unitrare

How to diagnose

Read the stored codes and freeze frame data to see engine load, speed and temperature when the fault set, and check for other sensor supply or related codes.
Inspect the sensor, connector and wiring for damage, chafing, water ingress, corrosion and loose pins.
Check any vacuum hose or pipe feeding the sensor for splits, blockages, oil contamination or poor fit, if fitted to your model.
With the ignition on, view live MAP and barometric readings. With the engine off, they should read close to ambient pressure. A reading near zero points to a fault.
Using the manufacturer wiring diagram, measure the reference voltage, earth and signal wire at the sensor connector.
Check the signal, supply and earth wires for continuity and for shorts to earth or each other, with the connector disconnected from both ends.
Compare the live MAP reading with the actual manifold pressure at idle and with the engine off, using a known-good gauge, to confirm whether the sensor is at fault.
If the wiring and supply are sound and a known-good sensor does not cure it, test the control unit supply and earths before considering the unit itself.

How to fix

Replace the MAP or barometric pressure sensor if it fails the voltage or live data checks.
Repair or replace damaged wiring and clean or renew corroded or loose connector terminals.
Restore the 5 volt reference or earth by repairing the circuit fault found during testing.
Renew or refit any split, blocked or disconnected vacuum hose to the sensor.
Repair or replace the engine control unit only after all wiring and sensor faults are ruled out, following the manufacturer's procedure.

Can I keep driving?

Medium severity

The car can usually be driven for a short time, but poor running, rich mixture and possible limp mode mean it should be repaired soon. Avoid long journeys or heavy loads, and stop if the engine stalls or runs very badly.

Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.