P0107 Generic (SAE)

Manifold Absolute Pressure / Barometric Pressure Circuit Low Input

Updated 2026-10-02 · Fuel & air metering

Severity

Medium

Typical repair cost

25 – 280 EUR

System

Powertrain

What it means

The ECU expects the MAP signal to stay above roughly 0.2-0.3 V even at the deepest possible manifold vacuum (about 10-15 kPa on deceleration). P0107 sets when the signal drops below that floor, typically for more than 1-2 seconds, which means the signal wire is open, shorted to ground, or the sensor has lost its 5 V supply. The ECU falls back to a default pressure value and ignores the sensor.

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Symptoms

Check engine light on immediately after start
Engine runs lean: hesitation, surging, popping on overrun
Hard starting, especially cold, as the ECU assumes low load
Reduced power, poor throttle response
On turbo diesels and petrols: boost control inactive or limited

Common causes

Signal wire shorted to ground after chafing on the manifold or a bracket
Open 5 V reference wire or corroded reference pin at the sensor
Sensor internal failure driving the output to ground
Connector unplugged or terminals pushed back after recent engine work
Short in another sensor sharing the same 5 V reference dragging the supply down
ECU reference regulator fault (rare)

How to diagnose

Check freeze frame: MAP reading near 0 kPa with the engine running confirms the circuit fault rather than a real vacuum reading
Key on, measure the sensor's reference pin: must be 4.9-5.1 V; if below 4.5 V, unplug other 5 V sensors one by one (TPS, fuel rail pressure, AC pressure) to find the one pulling it down
Measure the signal pin with the sensor connected, key on, engine off: should be 4.0-4.7 V; 0 V indicates a dead sensor or a grounded signal wire
Unplug the sensor and measure the signal wire alone: should float to about 5 V from the ECU pull-up; if it reads 0 V the harness is shorted to ground or open
Check ground pin: under 0.1 V to battery negative with the engine running
Swap in a known-good sensor or apply a jumper from reference to signal briefly (ECU should read full-scale pressure) to prove the ECU input works

Frequently asked questions

Why did P0107 appear together with P0122 or P0192?

All those sensors share the ECU's 5 V reference. One shorted sensor pulls the reference down and every sensor on it reads low simultaneously.

Can I just unplug the MAP sensor to drive home?

The engine will run on default values and most likely drive, but with poor power and economy. Fix it soon to avoid lean-running damage to the catalyst.