P0107 on 2006-2011 Honda Civic: MAP Sensor Circuit Low Causes and Fixes

What's Unique About the 2006-2011 Honda Civic

On the 8th generation Honda Civic (R18 and K20 engines), the MAP sensor is a very common and well-documented failure point among owners. While wiring issues or vacuum leaks can trigger this code, the sensor itself is the most frequent culprit due to age and heat cycles. A key feature of this platform is the sensor's location on top of the intake manifold, making it exceptionally easy to access and replace with a single bolt, which is why many owners perform this repair themselves.

Symptoms You May Notice

• Check Engine Light is on
• Rough, erratic, or hunting idle
• Engine stalling, especially at stops or low speeds
• Hesitation, sluggish acceleration, or lack of power
• Noticeably reduced fuel economy (10-20% drop is possible)
• Black smoke from the exhaust (indicating a rich fuel mixture)
• Hard starting or a "crank, no start" condition
• Engine pinging or detonation sounds during acceleration
• Strong gasoline smell from the exhaust
🎬 Watch: See these symptoms and where the sensor is located.

Most Likely Causes

1. Faulty MAP Sensor 🔴 High Probability → Shop Manifold Absolute Pressure Sensor The sensor is a common failure item on this platform due to age and constant heat cycles in the engine bay, leading to internal electronic failure.
   How to confirm: With the key on and engine off (KOEO), backprobe the sensor's signal wire. A reading below ~0.5V when it should be around 4.5-5.0V points to a bad sensor or circuit issue. Given the high failure rate and low part cost, many owners replace it based on the code and symptoms alone after a quick visual check of the wiring.
   Typical fix: Replace the MAP sensor. It is held in by a single 8mm or Phillips head screw 🎬 Watch: A step-by-step guide to testing and replacing the sensor. on the intake manifold.
   Est. part cost: $25-$135
2. Damaged Wiring or Connector 🟡 Medium Probability Engine vibration and heat can cause wires to become brittle, frayed, or shorted over time, especially within the harness loom. The connector's locking tab can also break, leading to a poor connection.
   How to confirm: Visually inspect the wiring harness leading to the MAP sensor for chafing, melting, or corrosion. Wiggle the connector with the engine running to see if it affects the idle (a "wiggle test"). Use a multimeter to confirm 5V reference and a good ground at the connector pigtail. A user on YouTube found a broken wire hidden inside the loom after the code persisted with a new sensor.
   Typical fix: Repair the damaged section of wiring or replace the pigtail connector. Pigtails are available as aftermarket parts.
   Est. part cost: $10-$30
3. Vacuum Leak ⚪ Low Probability Rubber and plastic vacuum hoses connected to the intake manifold can crack, become brittle, and leak with age. A stuck-open PCV valve can also act as an internal vacuum leak.
   How to confirm: Visually inspect all vacuum hoses for cracks or loose fittings. A common DIY method is to spray starter fluid or brake cleaner near suspected leak points with the engine running; a change in idle indicates a leak. A professional mechanic will use a smoke machine for a definitive diagnosis. A Reddit user fixed P0107/P0108 codes by replacing a stuck PCV valve.
   Typical fix: Replace the cracked vacuum hose or faulty PCV valve.
   Est. part cost: $5-$30

Rare But Worth Checking

• Faulty Powertrain Control Module (PCM): → Shop Engine Control Module (ECM) This is extremely rare and should only be considered after all other possibilities (sensor, wiring, vacuum leaks) have been definitively ruled out. The PCM is the last thing to suspect.
• Clogged Air Filter or Restricted Exhaust: A severely clogged engine air filter or a blocked catalytic converter can alter intake manifold pressure enough to confuse the sensor, though this will usually be accompanied by other codes and severe performance loss.

Diagnosis Steps

1. Read the code with an OBD-II scanner to confirm P0107 is present and check for any other related codes.
2. Visually inspect the MAP sensor on top of the intake manifold. Ensure it's securely plugged in and the connector isn't damaged.
3. Inspect the wiring harness leading to the sensor. Look for obvious signs of damage, such as frayed wires, melting, or corrosion. Perform a 'wiggle test' on the harness and connector with the engine running to see if the idle changes.
4. Check for vacuum leaks. Visually inspect all rubber hoses connected to the intake manifold for cracks or loose connections. Also check the PCV valve and its hose.
5. If visual checks are clear, test the circuit with a multimeter. With the Key On, Engine Off (KOEO):
6. a. Check for 5V reference on the specified wire at the connector.
7. b. Check for a good ground (less than 0.1V or 100 millivolts).
8. c. Backprobe the signal wire. It should read approximately 4.5-5.0V at KOEO (matching atmospheric pressure). A reading below 0.5V indicates a fault in the circuit or sensor.
🎬 Watch: How to diagnose MAP sensor codes using a multimeter.
9. With the engine running at idle, the signal wire voltage should drop to around 1.0-1.8V, depending on engine vacuum. If the voltage doesn't respond correctly, the sensor is likely bad.
10. Given the high failure rate, low cost, and ease of replacement, many DIYers will replace the sensor if the initial visual and wiggle tests show no obvious wiring or vacuum issues.
11. After replacing the part, clear the code with the scanner and perform an ECM idle learn procedure. Take the vehicle for a test drive to ensure the problem is resolved.

Parts You'll Likely Need

• Manifold Absolute Pressure (MAP) Sensor (OEM #37830-RNA-A01) — This is the most common failure part for code P0107 on this vehicle. The internal electronics fail over time.
  Trusted brands: Honda (Genuine), Denso (OEM Supplier), NGK/NTK, Standard Motor Products (SMP)
  OEM price range: $70-$135
  Aftermarket price range: $25-$70

Related Codes That Often Appear With This One

• P0108 — P0108 is 'MAP Sensor Circuit High Input'. Seeing both P0107 and P0108 intermittently strongly suggests a wiring short, a loose connector, or a completely failed sensor sending erratic signals.
• P0171 — P0171 is 'System Too Lean'. A significant vacuum leak can cause both a lean condition and an incorrect MAP sensor reading, triggering both codes.
• P1129 — P1129 is a Honda-specific code for 'MAP Sensor Signal Higher Than Expected'. While different from P0107, it points to the same system and can appear in conjunction with MAP sensor issues.

Platform-Specific Known Issues

• Stuck PCV Valve: In some cases, particularly on the R18 engine, a PCV valve that is stuck open can create an internal vacuum leak sufficient to trigger P0107 and/or P0108 codes. An owner on Reddit reported this as the ultimate fix after cleaning the MAP sensor didn't work.

Mechanic-Grade Diagnostic Values

• MAP Sensor 5V Reference — expected: ~5.0 Volts. Failure: No voltage or significantly lower voltage indicates a problem with the PCM or the wiring.
• MAP Sensor Signal Voltage (KOEO) — expected: ~2.9 V to 4.9 V (depending on atmospheric pressure). Failure: A reading below 0.5V triggers P0107.
• MAP Sensor Signal Voltage (Hot Idle) — expected: 1.0V to 1.8V. Failure: Voltage that does not drop from the KOEO reading, or is stuck low, indicates a failed sensor or vacuum issue.
• MAP Sensor Ground Circuit Resistance — expected: Less than 10 Ω. Failure: Resistance above 10 Ω indicates a poor ground path, which can cause low voltage readings.

Scan Tool Commands That Help

• Honda HDS (or compatible): ECM/PCM Reset — Used to clear learned values from the computer before performing the idle learn procedure after replacing a MAP sensor or cleaning the throttle body.
• Generic OBD-II Scanner: Clear Fault Codes — Required after any repair to turn off the Check Engine Light. This should be followed by an idle learn procedure.
• Manual Procedure: ECM/PCM Idle Learn Procedure — Must be performed after replacing the MAP sensor, disconnecting the battery, or cleaning the throttle body to allow the ECU to relearn idle characteristics with the new sensor's parameters. The procedure involves running the engine at 3,000 RPM until the cooling fan cycles, then idling for 5 minutes.

Wiring & Ground Locations

• MAP Sensor Connector — On top of the intake manifold, plugged into the MAP sensor.. This is the primary point for testing. Pin 1 is the 5V reference, Pin 2 is the signal wire, and Pin 3 is the ground. Wire colors can vary, but on many models, the signal wire is Green/Red.
• G101 — On the thermostat housing, connecting to the engine wiring harness.. This is a critical ground point for the ECU and its sensors. A corroded or loose G101 ground is a known cause of erratic sensor readings and multiple, difficult-to-diagnose engine codes. A frayed wire in the loom near this ground can also be a culprit.
• ECM/PCM Connectors A, C, D — Behind the glove box or in the passenger-side kick panel area.. These connectors are the termination point for the MAP sensor wiring. For example, on some models, the MAP signal wire goes to pin D17. Checking for continuity and voltage at these pins can rule out a wiring break between the sensor and the computer.

Real Owner Repair Stories

• YouTube - Pine Hollow Auto Diagnostics (Chevrolet Malibu (similar 3-wire MAP sensor design)) — P0107 code present.
  ❌ Tried (didn't work) Initial assumption was a bad MAP sensor.
  ✅ What actually fixed it After confirming 5V reference and good ground at the connector, the technician discovered a broken signal wire hidden inside the protective wire loom a few inches back from the connector. The fix was to cut out the bad section of wire and splice in a new piece using a non-insulated butt connector and marine-grade heat shrink.

OEM Part Supersession History

• 37830-RNA-A01 → N/A - Still the primary part number.
  Heads up: This part number is widely cross-referenced with 37860-RNA-A01 and 37830-RWC-A01. While they may fit, it is critical to use the exact OEM part number for the vehicle's VIN to ensure correct calibration. Aftermarket sensors from brands like Denso (an OEM supplier) are generally reliable alternatives.

Diagnostic Flowchart

Real Owner Stories

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

Related OBD-II Codes

• P0108 — Manifold Absolute Pressure/Barometric Pressure Circuit High Input. This is the direct opposite of P0107 and frequently appears alongside it on the Civic when there is a stuck PCV valve or an intermittent wiring short.
• P0172 — System Too Rich (Bank 1). A faulty MAP sensor reading low pressure will cause the ECM to miscalculate fuel delivery, often resulting in the rich fuel mixture, black smoke, and strong gas smell noted in the symptoms.
• P0300 — Random/Multiple Cylinder Misfire Detected. The erratic fuel trims caused by the failing MAP sensor or a vacuum leak can lead to engine pinging, detonation, and rough idle, triggering misfire codes.
• P0507 — Idle Air Control System RPM Higher Than Expected. Often triggered alongside P0107 if the root cause is a vacuum leak (like a cracked hose or stuck PCV valve) causing a hunting or erratic idle.

Frequently Asked Questions