P0107 – Manifold Absolute Pressure/Barometric Pressure Circuit Low Input

P0107 is an OBD-II trouble code that points to a problem with your engine’s MAP (Manifold Absolute Pressure) sensor circuit reading too low. In plain language, your engine computer is seeing a voltage signal from the MAP sensor that doesn’t make sense, so it turns on the check engine light. When this happens, you may notice hard starting, rough idle, poor fuel economy, or even stalling. The good news is that with some basic tools and a systematic approach, you can track down the cause and fix it before it leads to bigger issues.

What Does P0107 Mean?

P0107 stands for “MAP Sensor Circuit Low Input.” Your engine control unit (ECU) expects the MAP sensor to send a voltage signal within a certain range based on engine load and intake manifold pressure. When the signal drops below a calibrated minimum (usually under about 0.25–0.5 volts), the ECU sets P0107.

This low-voltage condition can be caused by a bad sensor, wiring issues, a poor ground, or in some cases a real vacuum/pressure problem. The ECU may respond by going into a backup or “limp” mode, which affects performance and fuel economy.

Quick Reference

• Code: P0107 – MAP Sensor Circuit Low Input
• System: Engine air/fuel and load calculation
• Common Symptoms: Hard start, rough idle, low power, poor MPG
• Usual Culprits: Faulty MAP sensor, wiring/connector damage, vacuum issues
• Severity: Moderate to severe – can cause stalling and drivability issues

Real-World Example / Field Notes

In the shop, I see P0107 a lot on daily drivers that have some miles and heat cycles on them. A typical case: a compact sedan comes in with a check engine light, rough idle, and poor fuel economy after a hot day in traffic. Scan tool shows P0107 and fuel trims pegged rich. A quick visual check reveals an oil-soaked MAP sensor connector and brittle wiring loom. After cleaning the connector, repairing a cracked wire, and clearing the code, the car idles smoothly and fuel trims return to normal. Many P0107 cases end up being simple wiring or connector problems, not always the sensor itself.

Symptoms of P0107

• Check engine light on: P0107 will usually store as an active or pending code.
• Hard starting: The engine may crank longer or struggle to fire, especially when hot.
• Rough idle: Unstable idle speed, shaking, or misfire-like feel at stoplights.
• Low power: Sluggish acceleration, poor throttle response, and lack of power under load.
• Poor fuel economy: The ECU often enriches the mixture, causing higher fuel consumption.
• Stalling: Engine may stall when coming to a stop or when shifting into gear.
• Black smoke or fuel smell: Excessively rich mixture can cause dark exhaust or fuel odor.
• Surging or hesitation: Inconsistent MAP data can cause jerky or uneven power delivery.

Common Causes of P0107

Most Common Causes

• Faulty MAP sensor: Internal failure from age, contamination, or moisture intrusion.
• Damaged wiring harness: Broken, shorted, or rubbed-through wires between MAP and ECU.
• Corroded or loose connector: Green corrosion, bent pins, or loose fit at the MAP plug.
• Short to ground: MAP signal wire contacting metal or another ground circuit, pulling voltage low.
• Poor MAP ground or 5V reference: Weak ground or low reference voltage causing low output signal.

Less Common Causes

• Intake manifold vacuum issues: Severe vacuum leaks or restrictions confusing the MAP reading.
• Incorrect aftermarket parts: Wrong MAP sensor or cheap universal replacement with wrong calibration.
• ECU internal fault: Rare, but a failing engine computer can misread or pull down the MAP signal.
• Water or oil contamination: Fluid intrusion in the connector or sensor body affecting voltage output.
• Previous wiring repairs: Poor splices, twisted wires, or wrong gauge wire from earlier work.

Diagnosis: Step-by-Step Guide

You’ll ideally have a basic OBD-II scan tool, a digital multimeter, and some contact cleaner. A wiring diagram or service info for your specific vehicle helps a lot. If you’re comfortable with light electrical work and careful testing, you can narrow down P0107 at home.

1. Confirm the code and freeze-frame data. Scan for codes and note engine load, RPM, MAP reading, and temperature when P0107 set. Clear codes and see if it returns during a short drive.
2. Compare live MAP data. With the key on/engine off, MAP should read close to barometric pressure (usually 95–105 kPa or around 14–15 psi). At idle, it should drop significantly. If it’s stuck very low, that supports P0107.
3. Inspect the MAP sensor and connector. Look for broken housings, oil or coolant contamination, cracked plastic, pulled wires, or loose retaining clips. Gently tug each wire to check for breaks under the insulation.
4. Check for vacuum hose issues (if hose-mounted MAP). Some MAP sensors use a short vacuum hose to the intake. Make sure it’s not cracked, soft, blocked, or disconnected. Replace any questionable hose.
5. Verify 5V reference and ground. With the key on, back-probe the MAP connector. You should see about 5 volts on the reference wire and close to 0 volts on ground. If 5V is missing or low, you may have a shared circuit issue with other sensors.
6. Measure MAP signal voltage. Still key on, check the signal wire. It should typically be around 4–4.5 volts with engine off (depending on design). If it’s near 0 volts, unplug the sensor. If the signal jumps up when unplugged, suspect the sensor. If it stays low, suspect wiring or ECU.
7. Wiggle test the harness. While watching live data or your meter, gently move the wiring harness around the MAP sensor and along the route to the ECU. If readings jump or the engine stumbles, you’ve likely found a wiring fault.
8. Check for shorts to ground. With the sensor unplugged and key off, use your meter to check resistance between the signal wire and ground. Very low resistance indicates a shorted wire or internal ECU problem.
9. Use Mode $06 (if available). Some scan tools can access Mode $06 to see detailed test results for the MAP circuit. This can confirm intermittent failures even when the code isn’t active.
10. Substitute a known-good sensor (if possible). If power, ground, and wiring check out, installing a known-good or new quality MAP sensor is often the final test.

Pro tip: If you have multiple sensor codes involving the 5V reference (like TPS or crank sensor codes along with P0107), always diagnose the 5V reference circuit first. One shorted sensor can drag the entire reference line down and create several “false” codes.

Possible Fixes & Repair Costs

Fixing P0107 usually involves restoring a clean, correct voltage signal from the MAP sensor to the ECU. Common repairs include replacing the MAP sensor, repairing or replacing damaged wiring, cleaning corroded connectors, or fixing vacuum hose issues. Typical repair costs at a shop range from about $100–$250 for a simple MAP sensor replacement, up to $300–$600 if wiring harness repair or extended diagnostics are needed. Costs vary with vehicle make, sensor location, labor rates, and whether other related components (hoses, connectors, brackets) must be replaced.

• Replace MAP sensor: Straightforward on most vehicles; often the primary fix.
• Repair wiring/connector: Solder and heat-shrink splices, new pigtail connectors, or harness sections.
• Replace vacuum hose to MAP: Cheap and easy if your MAP uses a separate hose.
• Clean connector terminals: Use electrical contact cleaner and a small brush; repair any bent pins.
• ECU repair or replacement: Rare and usually only after all other causes are ruled out.

Can I Still Drive With P0107?

You can often still drive with P0107, but it’s not recommended for long. The ECU may run a rich backup strategy, which hurts fuel economy and can foul spark plugs or damage the catalytic converter over time. In some cases, the engine can stall unexpectedly, especially at idle or when coming to a stop, which is a safety concern. If the car runs very poorly, stalls, or won’t restart, you should avoid driving and have it towed to prevent further damage.

What Happens If You Ignore P0107?

If you ignore P0107, you risk long-term engine and emissions damage. A consistently rich mixture can overheat and poison the catalytic converter, dilute engine oil with fuel, and accelerate carbon buildup. You may also fail emissions testing and experience more frequent stalling or no-start situations. Addressing the code early is usually cheaper than fixing the damage caused by running it this way for months.

Related Pressure Manifold Codes

Compare nearby pressure manifold trouble codes with similar definitions, fault patterns, and diagnostic paths.

• P0108 – Manifold Absolute Pressure/Barometric Pressure Circuit High Input
• P0109 – Manifold Absolute Pressure/Barometric Pressure Circuit Intermittent
• P0106 – Manifold Absolute Pressure/Barometric Pressure Circuit Range/Performance
• P0105 – Manifold Absolute Pressure/Barometric Pressure Circuit
• P0192 – Fuel Rail Pressure Sensor Circuit Low
• P0102 – Mass or Volume Air Flow Circuit Low Input

Key Takeaways

• P0107 means your ECU sees a MAP sensor signal that is too low to be believable.
• Common causes include a bad MAP sensor, wiring faults, connector corrosion, or vacuum hose issues.
• Symptoms range from a simple check engine light to rough idle, stalling, and poor fuel economy.
• Diagnosis focuses on verifying 5V reference, ground, and signal voltage, plus a careful wiring and hose inspection.
• Most repairs are affordable if handled early; ignoring the code can damage the catalytic converter and other components.

Vehicles Commonly Affected by P0107

P0107 can show up on almost any OBD-II vehicle, but it’s particularly common on high-mileage compact cars, small SUVs, and trucks where heat and vibration are hard on sensors and wiring. You’ll frequently see this code on Chevrolet, GMC, Ford, Chrysler, Dodge, Jeep, Honda, Toyota, Hyundai, Kia, Nissan, and Volkswagen models. Many GM and Chrysler vehicles use MAP sensors heavily for load calculations, so wiring and connector issues on those platforms are especially common. Turbocharged engines that rely on accurate manifold pressure readings are also more sensitive to MAP circuit faults.

FAQ

Can I clear P0107 and keep driving without fixing it?

You can clear the code, but it will almost always come back if the underlying problem isn’t fixed. The ECU will still see the same low MAP signal and reset P0107, and you’ll keep dealing with poor drivability and possible long-term damage.

Is P0107 caused by a vacuum leak?

A vacuum leak can influence MAP readings, but P0107 is specifically about low circuit voltage. Most of the time, the cause is electrical (sensor, wiring, connector). However, on systems with a vacuum hose to the MAP, a collapsed or blocked hose can mimic a low signal condition.

How do I know if the MAP sensor itself is bad?

If you have proper 5V reference and ground, but the MAP signal stays low even with the sensor plugged in and no wiring issues found, the sensor is likely faulty. Comparing live data to expected values and, if possible, swapping in a known-good sensor is the most reliable way to confirm.

Can a bad MAP sensor damage my engine?

<pIndirectly, yes. A failing MAP sensor can cause the ECU to run the engine too rich or too lean. Over time, this can damage the catalytic converter, foul spark plugs, and contribute to carbon buildup. It’s not an instant failure, but it’s not something you want to ignore.

How long does it take to fix a P0107 code?

On most vehicles, diagnosis and repair can be done in about 1–2 hours if the issue is the sensor or a simple wiring fault. More complex harness problems or hard-to-access sensors may take longer. A shop with good diagnostic equipment can usually pinpoint the cause in a single visit.