P0107 on 2007-2011 Subaru Impreza: MAP Sensor Circuit Low Causes and Fixes

What's Unique About the 2007-2011 Subaru Impreza

On this generation of Subaru Impreza with the EJ253 engine, a P0107 code is a common and straightforward issue, almost always pointing to the MAP sensor or its immediate wiring. Unlike some other vehicles where vacuum leaks are a primary suspect for MAP codes, on the EJ253 engine, sensor failure is the leading cause. Owners will immediately notice the classic Subaru 'limp mode' behavior: a solid Check Engine Light accompanied by a flashing cruise control light and disabled vehicle dynamics control (VDC). This is the car's way of getting your attention and protecting the engine.

Symptoms You May Notice

• Check Engine Light is on
• Flashing Cruise Control light
• Vehicle Dynamics Control (VDC) / Traction Control is disabled
• Rough idle or stalling
• Hesitation or surging during acceleration
• Reduced engine power and poor performance (limp mode)
• Increased fuel consumption
• Difficulty starting the engine
• Black smoke from the exhaust

Most Likely Causes

1. Faulty Manifold Absolute Pressure (MAP) Sensor 🔴 High Probability → Shop Manifold Absolute Pressure Sensor The sensor is a common failure point due to age, heat cycles, and internal electronic failure, causing its output voltage to drop below the 0.5V threshold.
   How to confirm: With a scan tool, observe live MAP data. A reading of 13 kPa or below with the engine running points to a P0107 fault condition. Alternatively, with the key on and engine off, back-probe the signal wire at the sensor connector. A voltage reading below 0.5V points to a sensor or circuit issue. You can also test the sensor with a multimeter and vacuum pump to see if voltage changes correctly with applied vacuum.
   Typical fix: Replace the MAP sensor. It is located on the intake manifold near the throttle body and is typically held in by a single bolt. 🎬 Watch: How to test and replace your Subaru MAP sensor
   Est. part cost: $50-$270
2. Wiring Harness or Connector Issue 🟡 Medium Probability The wiring harness in the engine bay is exposed to heat and vibration, which can cause wires to break or insulation to crack, often inside the loom where it isn't visible. The connector itself can become loose, corroded, or have pins that lose tension.
   How to confirm: Visually inspect the MAP sensor connector and wiring for any signs of damage, corrosion, or loose pins. Unplug the connector and check for a 5V reference, a good ground, and continuity on the signal wire between the sensor and the ECM. Perform a 'wiggle test' on the harness while monitoring MAP voltage to see if the reading fluctuates, indicating an intermittent break.
   Typical fix: Repair the damaged section of the wire or replace the connector pigtail. Ensure the connector makes a solid, clicking connection to the sensor; a loose connection was a known issue on some Honda models with similar sensors, sometimes fixed with zip ties to ensure security.
   Est. part cost: $10-$50
3. Major Vacuum Leak ⚪ Low Probability
   How to confirm: While a vacuum leak can theoretically cause MAP sensor issues, a P0107 (low input) is less likely than a performance code (P0106). A massive leak would be required and would likely present with other severe symptoms. Still, inspect all vacuum hoses connected to the intake manifold for cracks, splits, or disconnections.
   Typical fix: Replace the leaking vacuum hose or gasket.
   Est. part cost: $5-$30

Rare But Worth Checking

• Clogged MAP Sensor Port: → Shop Manifold Absolute Pressure Sensor While much more common on the EE20 diesel engines due to soot buildup, it's theoretically possible for carbon deposits to block the small port on the intake manifold that the MAP sensor reads. Cleaning the port with an appropriate tool and intake cleaner can resolve the issue.
• Faulty Engine Control Module (ECM): → Shop Engine Control Module (ECM) This is very rare. Before condemning the ECM, all other possibilities, including the sensor, wiring, and connections, must be exhaustively ruled out. A failed input circuit inside the ECM can mimic a sensor or wiring fault.

Technical Service Bulletins (TSBs) & Recalls

Manufacturer service bulletins for related Subaru models highlight that electrical interference can sometimes trigger this code. For instance, TSB Bulletin #07-96-15 notes that a harness change was implemented to reposition the sensor and actuator wiring ground junction point to a location unaffected by engine movement, as the original configuration could set DTC P0107 in error.

Diagnosis Steps

1. Read the Code: Use an OBD-II scanner to confirm P0107 is the active code. Note any other codes present.
2. Check Live Data: With the scanner, view the live data for the MAP sensor. With the key on, engine off, the reading should be close to barometric pressure. At idle, it should show a deep vacuum (e.g., 30-32 kPa). A reading stuck at or below 13 kPa, or a voltage below 0.5V, indicates a problem.
3. Visual Inspection: Turn the engine off. Locate the MAP sensor on the intake manifold, near the throttle body. Inspect the sensor, its electrical connector, and the surrounding wiring for any obvious damage, corrosion, or loose connections.
4. Test the Circuit: Unplug the sensor. With the ignition on, use a multimeter to probe the connector terminals. You should find a 5-volt reference wire, a ground wire (near 0V), and a signal wire. If the 5V reference is missing, the problem is upstream in the wiring or ECM.
5. Test the Sensor: If the wiring seems okay, you can test the sensor itself. Reconnect it and use a T-pin to back-probe the signal wire. At idle, the voltage should be around 1.4-1.8 volts. If it's stuck below 0.5V, the sensor is almost certainly faulty.
6. Check for Vacuum Leaks: Although less common for this specific code, a large vacuum leak could be a factor. Inspect vacuum hoses for cracks or damage.
7. Replace the Part: If the sensor is identified as the fault, replace it. It is typically held by one 8mm or 10mm bolt. Ensure the o-ring is properly seated to prevent a new vacuum leak.
8. Clear Code and Test Drive: After replacing the part, clear the code with your scanner and perform a test drive to ensure the issue is resolved and the code does not return.

Parts You'll Likely Need

• Manifold Absolute Pressure (MAP) Sensor (OEM #22627AA470) — This is the most common failure part for a P0107 code on this vehicle. The internal electronics fail over time, causing the output voltage to drop below the minimum threshold. This part number replaces the older 22627AA350.
  Trusted brands: Subaru (OEM), Denso (Often the OEM manufacturer), NTK
  OEM price range: $250-$280
  Aftermarket price range: $40-$120

Related Codes That Often Appear With This One

• P0108 — Manifold Absolute Pressure/Barometric Pressure Circuit High Input. Seeing P0107 and P0108 together can indicate an intermittent electrical fault, a very erratic sensor, or a loose connector that is making and breaking contact.
• P0068 — MAP/MAF - Throttle Position Correlation. The ECM cross-references these sensors. A faulty MAP reading that is illogical compared to the MAF and throttle position data can trigger this code. A user on the FT86Club forum reported this code after an incorrect MAP sensor installation.

Mechanic-Grade Diagnostic Values

• MAP Sensor Live Data (Scan Tool) — expected: 30-32 kPa at idle.. Failure: A reading stuck at or below 13 kPa indicates a P0107 fault condition.
• MAP Sensor Signal Wire Voltage (at idle) — expected: 1.4V - 1.8V. Failure: Voltage is at or below 0.5V - 0.6V.
• MAP Sensor Connector - 5V Reference Pin — expected: ~5.0V with Key On, Engine Off.. Failure: No voltage or significantly lower voltage points to a wiring or ECM issue, not a sensor failure.
• MAP Sensor Connector - Ground Pin — expected: Less than 100 millivolts (0.1V) when tested against a known good ground.. Failure: Higher voltage or high resistance (over 1 ohm) to chassis ground indicates a bad ground path, which can cause an incorrect signal.
• MAP Sensor Signal Wire Voltage (Key On, Engine Off) — expected: ~4.5V - 5.0V (should reflect barometric pressure). Failure: A reading below this range with the engine off suggests a faulty sensor or circuit.

Wiring & Ground Locations

• MAP Sensor Connector (3-Pin) — On the MAP sensor, which is mounted to the intake manifold near the throttle body.. Knowing the pinout is critical for testing. On this vehicle's connector, when looking at the harness connector face, the pins are typically: Signal (Left), Ground (Middle), 5V Power (Right). This allows a technician to quickly test for power, ground, and signal integrity without a wiring diagram.

Real Owner Repair Stories

• Reddit user on r/subaru (2008 Subaru Outback Base Wagon) — P0107 code appeared after the user melted and re-wired their MAF (Mass Airflow) sensor connector.
  ✅ What actually fixed it This story is a cautionary tale, not a fix. The user was asking for the proper reset procedure after replacing the MAF sensor, but their issue highlights the common and costly mistake of confusing the MAF sensor with the MAP sensor, reinforcing the 'Common Misdiagnoses' section.

When the Usual Fixes Don't Work

• If replacing the MAP sensor does not fix the P0107 code, do not assume the new sensor is also faulty. The next step is to perform a full circuit integrity check. A common scenario that stumps DIY mechanics is a fault in the 5-volt reference circuit that is shared by multiple sensors. As detailed in 'Edge Case Failures', a short circuit in a different sensor, such as the throttle position sensor, can pull the voltage down for the entire circuit, causing the ECM to report a P0107 for the MAP sensor, even though the MAP sensor and its direct wiring are perfectly fine. Before condemning the ECM, every sensor sharing that 5V reference should be disconnected one by one to see if the voltage returns.

OEM Part Supersession History

• 22627AA350 → 22627AA470 — Standard part revision and improvement by the manufacturer.
  Heads up: None. The new part number is a direct replacement for the old one.

Diagnostic Flowchart

Other Known Issues on This Vehicle

Issues unrelated to this code that are worth knowing about as an owner of this generation:

• Head Gasket Failure 🔴 High — Very common on EJ253 engines, typically between 80,000 and 150,000 miles. Prone to external oil and/or coolant leaks.
• Timing Belt Replacement 🔴 High — This is a critical maintenance item. The belt must be replaced at or before the service interval of 105,000 miles or 105 months, whichever comes first. Failure of this belt on the interference EJ253 engine will cause catastrophic engine damage.
• Leaking Oil Pressure Switch / AVLS Solenoid 🟠 Medium — The oil pressure switches, particularly the one for the AVLS (Active Valve Lift System), are known to leak oil onto the exhaust manifold, causing a burning oil smell. This is a common and relatively easy fix.
• Premature Wheel Bearing Failure 🟠 Medium — Commonly reported failure, sometimes as early as 50,000-60,000 miles. Results in a humming or grinding noise that increases with vehicle speed.

Used vs. New Parts: Buying Guide for This Vehicle

When a used part is the smart pick: A used part is only recommended for the wiring connector pigtail if the original is physically damaged (e.g., broken locking tab, melted plastic). For the sensor itself, a used part is highly discouraged due to the high failure rate and unknown history.

Donor-vehicle mileage cap: roughly under 150000 miles for the part to have meaningful remaining life.

What to inspect on the donor part:

• For a connector pigtail, inspect for any signs of brittleness in the plastic.
• Ensure the wire insulation is flexible and not cracked.
• Check for clean, corrosion-free metal pins inside the connector.
• Ensure there is at least 4-6 inches of wire attached to make splicing easy.

OEM-only on this vehicle (don't cheap out):

• Manifold Absolute Pressure (MAP) Sensor

Aftermarket brands forum-validated for this vehicle:

• Denso (OEM supplier for Subaru)
• NTK

Brands owners have reported issues with on this vehicle:

• Unbranded, low-cost sensors from online marketplaces like Amazon or eBay are frequently reported as being unreliable or failing shortly after installation across many vehicle platforms.

Real Owner Stories

Aggregated from forums and TSBs cited above. Mileages and costs reflect what owners reported in those sources.

Related OBD-II Codes

• P0106 — A performance/range code for the MAP sensor that may appear instead of P0107 if the sensor is failing but not yet below the 0.5V threshold, or in the case of vacuum leaks.
• P0000 — General OBD-II scanners may show other codes alongside P0107; owners are advised to note all active codes during diagnosis. [Step 1]

Frequently Asked Questions