Your 8th Gen (FA5/FG2), 9th Gen (FB6/FG4), or 10th Gen (FC1/FK7) Civic may display diagnostic trouble code P0107 — which indicates a low voltage condition in the manifold absolute pressure sensor circuit.
P0107 is defined as “MAP Sensor Circuit Low Voltage”. This code indicates that the voltage signal from the MAP sensor is below the expected range. On a Honda, the MAP sensor output typically ranges from 0.5V AT idle (high vacuum) to approximately 4.5V at wide-open throttle. P0107 indicates the ECU is receiving a voltage below approximately 0.57V — a reading that corresponds to near-perfect vacuum, which is not physically possible at KOEO or during normal driving conditions.
This is a circuit fault, not a mechanical failure. It indicates the sensor’s electrical signal is missing, grounded out, or the sensor itself has failed. Before inspecting vacuum lines or fuel delivery components, perform electrical diagnostics using a digital multimeter (DMM). In the majority of cases, this code is caused by a failed sensor, corroded wiring, or — on older Civics — a known cold-weather issue addressed by a Honda TSB.
The following is a technical breakdown of the typical causes of P0107 on these Honda Civic models and the recommended diagnostic and repair procedures.
P0107 Diagnostic Overview: Low Voltage in MAP Circuit
P0107 (“MAP Sensor Circuit Low Voltage”) is an electrical fault, not a mechanical issue. The ECU is detecting that the voltage signal from the MAP sensor has dropped below 0.57V.
On a properly functioning Honda, the 3-wire MAP sensor should output approximately 2.9V at KOEO (Key On, Engine Off) based on atmospheric pressure, and sweep from 0.5V at idle to 4.5V at WOT. If the scanner shows near 0V or 2 kPa with the key on, the circuit is dead, the sensor is failed, or the wiring is damaged.
The MAP sensor circuit consists of three wires:
- Pin 1: 5V VCC reference from the ECU
- Pin 2: Signal wire back to the ECU
- Pin 3: Sensor ground
When the signal wire voltage drops below 0.57V, the ECU stores P0107.
Primary Failure Modes for P0107
1. Failed Sensor
The internal sensing element may fail. This is common on high-mileage R18 and K-series vehicles.
Recommendation: Use Denso or genuine OEM sensors. Aftermarket sensors may have incorrect calibration curves, affecting fuel trims and driveability.
2. Signal Wire Shorted to Ground
The signal wire may chafe against the engine block or brackets, causing the voltage to drop to 0V.
Test: With KOEO and the sensor disconnected, probe the signal pin to chassis ground. If continuity is present, the signal wire is shorted to ground. Trace and repair the wiring.
3. Missing 5V VCC Reference
If the 5V reference line is open or not providing voltage, the sensor cannot produce a signal.
Test: Disconnect the 3-pin connector. Set the DMM to DC volts. Probe Pin 1 (Reference) and Pin 3 (Ground) on the harness side.
Evaluation: If 5.0V (±0.5V) is present, the ECU and wiring are functional — the sensor is the issue. If 0V is present, inspect for rodent damage or wiring faults.
4. Cold Weather Freeze (TSB 04-004)
On older 6th Gen and early 7th Gen Civics in cold climates, moisture can condense inside the MAP sensor housing and freeze, causing low voltage readings and triggering P0107 or P0108. Honda issued TSB 04-004 to address this condition.
Remedy: Replace the MAP sensor. On Japan-built vehicles, the TSB also requires intake manifold replacement to correct condensation routing.
Diagnostic Procedure Using a DMM
Set the DMM to DC volts. Disconnect the MAP sensor connector and set the ignition to KOEO (Key On, Engine Off). Probe pins 1 and 3 on the harness side.
Evaluation:
- 5.0V ± 0.5V between pins 1 and 3: ECU and 5V reference are functional. The sensor or signal wire is the issue. Proceed to the signal test.
- 0V between pins 1 and 3: The ECU is not supplying 5V reference. Inspect the wiring for rodent damage or shorts. Check the ECU connector for bent or corroded pins.
Signal wire test: With the MAP disconnected and KOEO, probe pin 2 (signal) to chassis ground. If continuity is present, the signal wire is shorted to ground. Locate and repair the chafe point. If no continuity is present, the sensor is faulty — replace it.
Platform-Specific Considerations
8th Gen (FA5 / FG2 / R18):
- K20Z3 (Si): With aftermarket intakes, check the harness length near the intake tube. Tight installations can strain the MAP connector and cause intermittent P0107 codes.
- R18 (Base): Inspect for harness chafing at the plastic injector cover edges — a common failure point on high-mileage vehicles.
9th Gen (FB6 / FG4 / K24Z7):
- If using an aftermarket tune, verify MAP sensor scaling is correct in the calibration. Incorrect scaling in Hondata FlashPro or KTuner setups can cause false P0107 codes.
10th & 11th Gen Turbo (FC1 / FK7 / FL1 / FL5 / L15B7 / K20C1):
- This platform uses both a MAP sensor on the manifold and a boost pressure sensor on the charge pipes.
- If running an aftermarket tune from DRob (Innovative Motorworks) or Phearable, ensure all sensor connections are secure. Loose connectors or damaged wiring can cause the ECU to reduce timing as a safety measure.
- On the 1.5T, there are two sensors that can cause similar codes — the one on the manifold is the primary MAP.
OEM Part Numbers
Verify fitment by VIN before ordering.
| Part | Fits | OEM Part Number | Approx. Cost |
|---|---|---|---|
| MAP Sensor | 2006–2011 Civic Si K20Z3, 8th Gen R18, 9th Gen K24Z7 | 37830-PNC-003 | $80–$150 (dealer) / $50–$100 (online) |
| MAP Sensor | 2016–2021 Civic 1.5T L15B7 | 37830-RPY-G12 | $60–$120 (dealer) |
| MAP Sensor | 2017–2021 Civic Type R K20C1 | Verify by VIN | $70–$130 |
| MAP Sensor | 1996–2000 Civic EK/EM | Verify by VIN | $50–$100 |
Recommendation: Use OEM Honda or Denso sensors. Aftermarket sensors may have different voltage calibration curves, which can affect fuel trims and driveability.
Repair Cost Estimates
| Repair | DIY Cost | Independent Shop | Honda Dealer |
|---|---|---|---|
| MAP Sensor Replacement | $50–$150 (parts) | $180–$300 | $250–$400 |
| Wiring Repair (short to ground) | $10–$50 (materials) | $100–$200 | $150–$300 |
| Dealer Diagnostic Fee | N/A | N/A | $120–$200 |
Pricing based on current market rates from HondaPartsNow, RockAuto, and Majestic Honda.
TSB 04-004 — Cold Weather Freeze Issue
On 6th Gen (1996–2000) Civics in cold climates, Honda issued TSB 04-004 addressing condensation inside the MAP sensor housing. Moisture can freeze and cause low voltage readings, triggering P0107 or P0108. The repair involves replacing the MAP sensor. On Japan-built Civics, Honda also requires replacing the intake manifold.
If evaluating an older Civic where the seller indicates the code occurs only in cold weather, budget for MAP sensor replacement.
Pre-Purchase Inspection Note
When evaluating a used Civic with a P0107 code, the seller may claim it is a vacuum leak or tuning issue. P0107 is an electrical fault, not a mechanical one. A relatively inexpensive sensor replacement would typically resolve the issue.
On older Civics (1996–2000), P0107 may be related to the TSB 04-004 freeze issue in cold climates.
Recommendation: If the seller has not performed basic diagnostics, it may indicate neglect of proper maintenance. Consider this in price negotiation.
Diagnostic Checklist
☐ P0107 = MAP Sensor Circuit Low Voltage — electrical fault, not mechanical
☐ Check 5V reference at the sensor connector — should be ~5.0V between pins 1 and 3. No voltage = ECU or wiring problem
☐ Check signal wire for short to ground — disconnect sensor, probe pin 2 to chassis ground. Continuity = short in the harness
☐ On 1996–2000 Civic in cold climates: suspect TSB 04-004 — moisture freezing inside the MAP sensor
☐ Replace MAP sensor with genuine OEM — aftermarket sensors may have incorrect voltage calibration curves
☐ OEM part numbers: 37830-PNC-003 (K-Series), 37830-RPY-G12 (1.5T) — verify by VIN
☐ Avoid cheap aftermarket MAP sensors — incorrect calibration can affect fuel trims and timing
☐ If running a tune (Hondata FlashPro / KTuner), verify MAP scaling — custom e-tunes typically have correct scaling
☐ Inspect for rodent damage — Honda wiring is susceptible to rodent damage
☐ If the code returns after sensor replacement and wiring inspection, suspect ECM — rare but possible. Check the ECM connector for bent or corroded pins
☐ Pre-purchase inspection: P0107 is an electrical fault — use this information when evaluating the vehicle