P0107 Code: MAP Sensor Low Input Causes & Fixes

Quick answer

Code P0107 means the engine control module (ECM) sees a low voltage signal from the Manifold Absolute Pressure (MAP) sensor; below the expected minimum. This indicates a problem in the MAP sensor or its wiring, such as a short to ground, damaged harness, or a faulty sensor itself.

What "MAP Circuit Low Input" Actually Means

The MAP sensor measures intake manifold pressure to help the ECM calculate engine load and adjust fuel and spark timing. It typically outputs a 0.5-4.5 volt signal that varies with manifold pressure: low pressure (high vacuum, like at idle) produces low voltage (~0.5-1.0V), while high pressure (low vacuum, like at wide-open throttle) produces higher voltage (~4.0-4.5V).

When the ECM detects a MAP signal below ~0.2V for more than a few seconds, it logs P0107. This threshold is intentionally low to avoid false alarms from normal low-pressure conditions. A true low-input fault means the sensor circuit is electrically compromised; not just reading low due to engine conditions. Common triggers include:

How the ECM Diagnoses the Fault

The ECM runs a rationality check: it compares the MAP signal to other sensors (e.g., throttle position, mass airflow, crank/cam sensors). If the MAP voltage is abnormally low while throttle position or airflow suggests the engine should be under load, P0107 is set. For example, at idle, the ECM expects ~0.5-1.0V; if it sees 0.1V, it flags the code. On acceleration, if the MAP signal doesn't rise proportionally with throttle opening, the code may also trigger.

MAP Sensor vs. Circuit Issues

A low input doesn't always mean the MAP sensor is bad. The ECM can't distinguish between a sensor failure and a wiring issue on its own. A short to ground in the signal wire will pull voltage down, as will a damaged sensor internal circuit. The 5-volt reference wire or ground wire can also cause low readings if they're open or corroded; though these often trigger additional codes like P0106 (MAP range/performance) or P0110 (IAT circuit issues, if the MAP is a combo sensor).

Why This Matters for Engine Performance

With a falsely low MAP signal, the ECM assumes the engine is under less load than it actually is. This leads to incorrect fuel delivery; typically a lean fuel mixture; which can cause hesitation, poor acceleration, or even stalling. In some cases, the ECM may default to a pre-programmed fuel map, which is often too lean for real-world conditions, worsening drivability.

Symptoms of P0107

Drivers often notice rough idle, poor throttle response, or a lack of power during acceleration. In severe cases, the engine may stall or hesitate under load. These issues stem from the ECM misinterpreting engine load due to the low MAP signal.

Common Causes of P0107

The most frequent culprits are a faulty MAP sensor, a shorted or damaged signal wire, or a poor ground connection. Less commonly, a vacuum leak near the sensor can skew readings, though this usually triggers other codes first. Repairs typically range from $150 to $400 depending on the cause; see the full P0107 repair cost guide for a detailed breakdown.

Can You Still Drive With Code P0107?

Driving with P0107 is generally possible for short distances, but prolonged operation can lead to poor fuel economy, drivability issues, or even catalytic converter damage from a lean-running engine. If the vehicle stalls or runs roughly, have it towed to avoid further problems.

Details that improve the diagnosis

Compare the reported value with engine temperature, barometric pressure, throttle position and related sensors. A signal that is electrically valid can still be implausible. Fuel trims at idle and at a steady higher speed help separate an intake leak from a fuel-delivery or measurement problem.

Before clearing anything, record whether the code is current, pending, history or permanent. Save companion codes and freeze-frame conditions, then note recent repairs, a weak battery, weather changes and the exact moment the symptom appears. After a confirmed repair, clear only the erasable codes and complete the appropriate drive cycle. A permanent code normally clears only after the onboard monitor verifies that the fault is gone.

Related trouble codes

Information to record before any repair

Write down the exact code, its status and every companion code reported by a complete vehicle scan. Save the freeze-frame values, including engine speed, load, coolant temperature, vehicle speed, battery voltage and fuel trims when available. Note whether the warning appeared during a cold start, at idle, under acceleration, after refueling, in wet weather or immediately after other work. These details help separate an intermittent electrical problem from a repeatable mechanical or operating-condition fault.

Identify the exact year, make, model, engine, transmission and market version before using a wiring diagram or specification. Connector pinouts, monitor thresholds, component locations and test procedures can change within the same model line. Check current manufacturer service information and relevant technical service bulletins. A bulletin can improve the test sequence, but it should not be treated as proof that the same fault exists on every vehicle.

How to verify the repair

A warning light that stays off immediately after codes are cleared does not by itself confirm a repair. Recheck live data, repeat the operating condition that originally set the code when it is safe to do so, and confirm that no pending code returns. Some monitors need a specific drive cycle before they run. Permanent codes are normally removed by the control module only after it sees enough successful monitor results. If symptoms remain or the code returns, continue testing instead of replacing another part by guesswork.