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P0107 on 2012-2018 Ford Focus 2.0L: MAP Sensor Circuit Low Causes and Fixes

P0107 on a 2012-2018 Ford Focus almost always points to a faulty Manifold Absolute Pressure (MAP) sensor. This can cause stalling, a rough idle, and multiple warning lights like "Service AdvanceTrac". Replacing the sensor is the most common fix. The sensor is located on the intake manifold, making it a simple DIY job. An OEM part costs around $60-$105.

20 minutes to read 2012-2018 Ford Focus

Most Likely Cause

Faulty Manifold Absolute Pressure (MAP) Sensor

Difficulty

1/5

Est. Time

0.7 hrs

DIY Doable?

✅ Yes

Shop Labor

$80 – $250

Parts Price

$40 – $105

⚠️ Drivable, but... — You can drive, but it is not recommended. The engine may stall unexpectedly (sometimes in traffic), run rough, or have significantly reduced power, which can be a safety risk. The vehicle may enter a reduced-power "limp home" mode.

Key Takeaways

P0107 on your Focus means the MAP sensor circuit has low voltage.
The most likely cause is a failed MAP sensor itself, which is a relatively inexpensive and easy part to replace.
Symptoms can be severe, including stalling and loss of power, so it's best to address the issue promptly.
Before buying a new sensor, check its electrical connector and nearby wiring for any visible damage, as this is the second most common cause.
Don't be alarmed by other warnings like 'Service AdvanceTrac'; they are usually triggered by the engine fault and will clear once the P0107 code is resolved.

The trouble code P0107 stands for 'Manifold Absolute Pressure (MAP) / Barometric Pressure (BARO) Sensor Circuit Low Input'. This means the engine's computer, the Powertrain Control Module (PCM), has detected that the voltage signal from the MAP sensor is below the normal operating range, typically under 0.5 volts, and sometimes as low as 0.25 volts. The PCM relies on the MAP sensor to measure engine load by reading the pressure inside the intake manifold. A low voltage signal, which indicates very high vacuum, causes the PCM to miscalculate the air-fuel mixture and ignition timing, often leading to a rich fuel condition, black smoke, and poor engine performance.

What's Unique About the 2012-2018 Ford Focus

While P0107 is a generic code, Ford vehicles of this era, including the Focus, seem particularly prone to the MAP sensor itself failing and triggering this code. Authoritative documents for other Ford models like the Taurus and Explorer from the same period point directly to faulty MAP sensors as the cause. A common and well-documented symptom on these Fords is the simultaneous illumination of the Check Engine Light along with "Service AdvanceTrac" and "Hill Start Assist Not Available" messages. This occurs because the stability control systems rely on accurate engine torque data, which is lost when the MAP sensor provides an invalid low-voltage signal to the PCM.

Symptoms You May Notice

Check Engine Light is on
Engine stalling or dying, sometimes when coming to a stop
Rough or unstable idle
Lack of power and poor acceleration
Hesitation during acceleration
Warning messages such as "Service AdvanceTrac" and "Hill Start Assist Not Available"
Reduced fuel economy
Hard starting, requiring long cranking times
Black smoke from the exhaust

⚠️ Don't Waste Money on the Wrong Fix

Replacing the throttle body or other sensors without first diagnosing the MAP sensor circuit.
Replacing the MAP sensor when the actual fault is in the wiring or connector.

Most Likely Causes

Faulty Manifold Absolute Pressure (MAP) Sensor 🔴 High Probability The sensor's internal electronics can fail from heat and vibration over time. Ford issued TSBs for similar issues on other models, indicating a known weakness in sensors from this period. The sensor is the most common failure point for this code.
How to confirm: After checking wiring, test the sensor. With the key on and engine off, the signal wire should read a specific voltage based on altitude. With a vacuum pump applied to the sensor, the voltage should decrease smoothly. A static low voltage (under 0.5V) regardless of vacuum or engine state points to a bad sensor. The sensor is located on the top of the intake manifold.
Typical fix: Replace the MAP sensor. It is located on the intake manifold and secured with one or two bolts, making it easily accessible.
Est. part cost: $40-$105
Wiring or Connector Issue 🟡 Medium Probability The wiring harness in the engine bay is exposed to heat and vibrations, which can cause wires to break or insulation to crack over time, leading to a short to ground or an open circuit.
How to confirm: Visually inspect the MAP sensor connector and its wiring for any signs of damage, corrosion, or loose pins. Use a multimeter to check for a 5V reference voltage and a good ground at the connector with the key on. Perform a "wiggle test" on the harness while the engine is running to see if it causes the idle to change.
Typical fix: Repair the damaged section of wire or replace the connector pigtail. Apply dielectric grease to the new connector to prevent future corrosion.
Est. part cost: $10-$30
Major Vacuum Leak ⚪ Low Probability While less common for a 'circuit low' code, a massive vacuum leak from a cracked intake manifold or disconnected hose could theoretically cause erratic sensor readings, though it more commonly triggers other codes. The canister purge valve on the 2.0L GDI engine is a known failure point that can cause excessive vacuum and drivability issues.
How to confirm: With the engine running, listen for hissing sounds around the intake manifold. You can also carefully spray brake cleaner or a propane torch (unlit) around suspected areas; a change in engine idle indicates a leak. A smoke test is the most effective way to find a leak.
Typical fix: Replace the leaking gasket, hose, or faulty canister purge valve. In some cases, the plastic intake manifold itself may be cracked and require replacement.
Est. part cost: $5-$300

Rare But Worth Checking

Faulty Powertrain Control Module (PCM): This is the least likely cause. The PCM should only be considered after the sensor, wiring, and all other possibilities have been definitively ruled out.

Diagnosis Steps

Connect an OBD-II scanner to verify P0107 is the primary code. Note any other codes present, especially P0106 or P0108.
With the scanner, check the live data for the MAP sensor reading (both pressure and voltage) with the Key On, Engine Off (KOEO). The pressure should be close to atmospheric pressure for your altitude. The voltage should be between 1.0V and 4.5V. A reading below 0.5V indicates a problem.
Visually inspect the MAP sensor on the intake manifold, its electrical connector, and the surrounding wiring for obvious damage, corrosion, or loose connections.
Disconnect the sensor and test the connector with a multimeter (KOEO). You should find a 5-volt reference wire, a ground wire (near 0 volts), and a signal wire.
If the 5V reference or ground is missing, trace the wiring back to the PCM to find the break or short.
If reference voltage and ground are good, reconnect the sensor. Back-probe the signal wire with the multimeter. If the voltage is stuck below 0.5V, the sensor is almost certainly bad.
As a final confirmation, you can jump the 5V reference wire to the signal wire at the connector. The scanner's live data for MAP voltage should jump to 5V. If it does, the wiring to the PCM is good, confirming a failed sensor.
If the sensor and wiring test good, check for a clogged catalytic converter or a major vacuum leak, although these are less likely for a 'circuit low' code.
If all other possibilities are exhausted, the final possibility is a fault within the PCM, which is rare.

Parts You'll Likely Need

Manifold Absolute Pressure (MAP) Sensor (OEM #CV2Z-9F479-B) — This is the most frequent point of failure for code P0107 on this vehicle, as supported by owner experiences and Ford's own technical service bulletins for similar models.
Trusted brands: Motorcraft, Bosch, NGK, Standard Motor Products (SMP), Delphi
OEM price range: $60-$105
Aftermarket price range: $40-$75

Related Codes That Often Appear With This One

P0106 — P0106 indicates a MAP sensor performance/range issue. It can appear alongside P0107 if the sensor's signal is erratic before failing completely low.
P0108 — P0108 is for MAP sensor circuit high input. It's the opposite of P0107 but can be seen if there are intermittent wiring shorts or if it's part of a pattern identified by Ford TSBs for this sensor family.

Technical Service Bulletins (TSBs) & Recalls

TSB 19-2212 / 19-2183: Although for different Ford models with EcoBoost engines, it directly links P0107, P0108, and/or P0109 to a faulty MAPT sensor causing a lack of power and multiple warning messages, establishing a known pattern for Ford vehicles of this era.

Platform-Specific Known Issues

A Ford Technical Service Bulletin (TSB 19-2212, later superseded by 19-2183) for other models of the same era identifies a faulty MAP sensor as the cause for P0107, often accompanied by "Service AdvanceTrac" and "Hill Start Assist Not Available" messages, which is a pattern also reported by owners.
An owner complaint to NHTSA (ODI #11351923) for a similar Ford model describes the vehicle stalling in the middle of an intersection due to a faulty MAP sensor triggering code P0107, highlighting the potential safety risk.
Owners on forums like FocusFanatics and Reddit frequently report that replacing the MAP sensor (Part No. CV2Z-9F479-B) is the definitive fix for a P0107 code accompanied by stalling and AdvanceTrac warnings.

Mechanic-Grade Diagnostic Values

MAP Sensor Voltage (KOEO - Key On, Engine Off) — expected: ~4.5V (at sea level, decreases with altitude). Failure: Voltage is below 0.5V, indicating a circuit low fault.
MAP Sensor Voltage (Engine Idling) — expected: 0.9V - 1.3V (high vacuum). Failure: Voltage remains below 0.5V and does not change with engine RPM.
MAP Sensor Pressure (Engine Idling, warm) — expected: 28-32 kPa. Failure: Reading is static or does not correlate with engine load changes.
MAP Sensor Connector - Reference Voltage — expected: 5.0V on the reference wire from the PCM.. Failure: Voltage is significantly lower than 5.0V or absent, indicating a wiring or PCM issue.
MAP Sensor Connector - Ground Circuit — expected: Near 0V.. Failure: Voltage is present on the ground wire, indicating a bad ground connection.

Scan Tool Commands That Help

Ford IDS (Integrated Diagnostic System): KOER (Key On, Engine Running) Self-Test — To command the PCM to run a full system check while the engine is running, which can help identify intermittent faults or confirm if the P0107 code returns immediately after being cleared.
Ford IDS (Integrated Diagnostic System): Datalogger - Monitor MAP_V (Voltage) and MAP (Pressure) PIDs — To view live data from the MAP sensor while performing wiggle tests on the harness or applying vacuum with a hand pump, which helps isolate a faulty sensor from a wiring issue.
OBD-II Scanner (Advanced): Clear KAM (Keep Alive Memory) — After replacing the MAP sensor or repairing a wiring fault, clearing the KAM resets the PCM's adaptive learning tables. This forces the computer to relearn fuel trims and sensor values immediately with the new, correct data, which can resolve lingering performance issues.

Wiring & Ground Locations

G100 / G102 / G104 — Various points on the left side of the engine compartment, near the battery junction box and front of the motor assembly.. These are primary engine bay ground points. Corrosion or a loose connection at these locations can create a floating ground, causing erratic voltage readings for multiple sensors, including the MAP sensor, potentially triggering a P0107 code.
MAP Sensor Connector — On the MAP sensor itself, which is mounted to the front of the intake manifold on the 2.0L engine.. This 3-pin connector provides the 5V reference, ground, and signal return for the sensor. It is a common failure point due to vibration and heat, leading to intermittent or total loss of signal. The Ford part number for the connector pigtail is HC3Z-14S411-A.
Ground Point under Air Box — Underneath the air filter box assembly in the engine bay.. This is a major chassis ground point that serves multiple engine components. Owners performing a 'ground mod' often clean and improve this connection to resolve various electrical issues, including those related to the transmission control module and engine sensors.

Real Owner Repair Stories

Reddit user in r/FordFocus (2008 Ford Focus, 200,000 miles (Note: Mk2, but diagnosis is relevant)) — Persistent P0107 code, smooth idle, good gas mileage.
❌ Tried (didn't work) Replaced MAP sensor, Cleaned throttle body, Replaced injectors, plugs, wires, and coils for a separate misfire code
✅ What actually fixed it The issue was identified by another user as a likely wiring problem ('circuit code'), not a sensor failure. The final fix was not posted, but the diagnosis shifted from parts replacement to checking the circuit integrity between the sensor and the computer, which is the correct next step when a new sensor doesn't solve a circuit code.

OEM Part Supersession History

CV2Z-9F479-A → CV2Z-9F479-B — Standard part revision by the manufacturer for improved reliability or a change in supplier.
Heads up: The parts are interchangeable. CV2Z-9F479-B is the current service part for the specified vehicle range.
CM5E-9F479-A → CV2Z-9F479-B (also listed as CX2423) — Part number consolidation and revision. The base number 9F479 is used across many Ford models, with the prefix changing based on the vehicle application and revision.
Heads up: While physically similar, always verify fitment using the vehicle's VIN. The CM5E prefix was associated with early Focus models and may have different calibration from the later CV2Z part.

Diagnostic Flowchart

Start by verifying if P0107 is accompanied by 'Service AdvanceTrac' or stalling, as these symptoms often point to a specific sensor failure on the Ford C1 platform.

Check live data for MAP voltage with Key On, Engine Off (KOEO). Is the reading below 0.5V?

Unplug the MAP sensor. Test the connector pins for 5V reference and ground. Are they present?

→ The MAP sensor (Part No. CV2Z-9F479-B) has failed internally. This is a known issue on 2012-2018 Focus models. Replace the sensor located on top of the intake manifold.

→ Inspect the wiring harness for breaks or shorts to ground caused by engine vibration. Repair the damaged wire or replace the connector pigtail.

Perform a smoke test or listen for hissing. Is there a massive vacuum leak at the intake manifold?

→ Repair the leaking hose or replace the intake manifold gasket. If the plastic manifold is cracked, it must be replaced.

Jump the 5V reference wire to the signal wire at the connector. Does the scanner show 5V?

→ The wiring to the PCM is intact. Replace the MAP sensor, as it is failing to send a signal under load despite passing static tests.

→ The fault lies in the PCM or the signal wire deep in the main harness. This is rare; re-verify all grounds before considering PCM replacement.

Does the engine stall specifically after refueling or exhibit a very rough idle?

→ Check the Canister Purge Valve (CPV). This is a high-failure item on the 2.0L GDI engine (Recall 18S32). A stuck valve can cause vacuum issues that trigger P0107.