Diagnostic Trouble Code (DTC) Quick Reference — Honda Civic
A quick-reference guide to the most common Diagnostic Trouble Codes (DTCs) encountered on Honda Civic models. These standardized OBD-II codes help identify issues with the engine, transmission, and emissions systems. Always confirm the code with a diagnostic scanner before performing repairs.
| Code | Description | Common Causes | Affected Generations |
|---|---|---|---|
| P0010 | Variable Valve Timing Control (VTC) Oil Control Solenoid Valve Malfunction | Failed VTC solenoid, wiring issue, timing chain stretch, low oil pressure | 6th–11th gen |
| P0011 | Variable Valve Timing Control (VTC) System Malfunction | Failed VTC solenoid, timing chain stretch, camshaft sensor issue, low oil | 6th–11th gen |
| P0101 | Mass Air Flow (MAF) Circuit Range / Performance Problem | Dirty MAF sensor, vacuum leak, air intake leak, fuel pressure issue | All OBD-II (1996+) |
| P0107 | Manifold Absolute Pressure (MAP) Sensor Circuit Low Input | Failed MAP sensor, vacuum leak, wiring issue, intake manifold leak | All OBD-II (1996+) |
| P0108 | Manifold Absolute Pressure (MAP) Sensor Circuit High Input | Failed MAP sensor, wiring short, PCM issue, vacuum line disconnected | All OBD-II (1996+) |
| P0111 | Intake Air Temperature (IAT) Sensor Circuit Range / Performance Problem | Failed IAT sensor, wiring issue, air intake leak, sensor contamination | All OBD-II (1996+) |
| P0113 | Intake Air Temperature (IAT) Sensor Circuit High Input | Failed IAT sensor, wiring short, PCM issue, sensor connector corrosion | All OBD-II (1996+) |
| P0116 | Engine Coolant Temperature (ECT) Sensor Circuit Range / Performance | Failed ECT sensor, thermostat stuck, wiring issue, coolant leak | All OBD-II (1996+) |
| P0118 | Engine Coolant Temperature (ECT) Sensor Circuit High Input | Failed ECT sensor, wiring short, PCM issue, sensor connector corrosion | All OBD-II (1996+) |
| P0122 | Throttle / Pedal Position Sensor / Switch A Circuit Low Input | Failed TPS sensor, wiring issue, connector corrosion, PCM problem | All OBD-II (1996+) |
| P0128 | Coolant Thermostat (Coolant Temp Below Thermostat Regulating Temperature) | Stuck-open thermostat, failed ECT sensor, wiring issue, coolant leak | 7th–11th gen |
| P0134 | O2 Sensor Circuit No Activity Detected (Bank 1 Sensor 1) | Failed upstream O2 sensor, wiring open, connector corrosion, PCM issue | All OBD-II (1996+) |
| P0135 | O2 Sensor Heater Circuit Malfunction (Bank 1 Sensor 1) | Failed upstream O2 sensor heater, wiring issue, blown fuse, PCM problem | All OBD-II (1996+) |
| P0139 | O2 Sensor Circuit Slow Response (Bank 1 Sensor 2) | Aging downstream O2 sensor, exhaust leak, fuel system issue, wiring problem | All OBD-II (1996+) |
| P0141 | O2 Sensor Heater Circuit Malfunction (Bank 1 Sensor 2) | Failed downstream O2 sensor heater, wiring issue, blown fuse, PCM problem | All OBD-II (1996+) |
| P0171 | System Too Lean (Bank 1) | Vacuum leak, MAF sensor issue, fuel pump failure, fuel filter restriction, injector leak | All OBD-II (1996+) |
| P0172 | System Too Rich (Bank 1) | Failed MAF sensor, faulty O2 sensor, fuel pressure regulator issue, leaking injector | All OBD-II (1996+) |
| P0300 | Random / Multiple Cylinder Misfire Detected | Faulty ignition coils, worn spark plugs, vacuum leaks, fuel delivery issues, low compression | All OBD-II (1996+) |
| P0301 / P0302 / P0303 / P0304 | Cylinder 1–4 Misfire Detected | Ignition coil failure (specific cylinder), spark plug, fuel injector, compression issue | All OBD-II (1996+) |
| P0325 | Knock Sensor 1 Circuit (Bank 2 or Single Sensor) | Failed knock sensor, wiring issue, connector corrosion, PCM problem | All OBD-II (1996+) |
| P0328 | Knock Sensor 1 Circuit High Input (Bank 2 or Single Sensor) | Failed knock sensor, wiring short, PCM issue, sensor connector corrosion | All OBD-II (1996+) |
| P0335 | Crankshaft Position Sensor Circuit Malfunction | Failed CKP sensor, wiring damage, tone ring issue, connector corrosion | All OBD-II (1996+) |
| P0336 | Crankshaft Position Sensor A Circuit Range / Performance | Failed CKP sensor, wiring issue, tone ring damage, timing chain stretch | All OBD-II (1996+) |
| P0339 | Crankshaft Position Sensor A Circuit Intermittent | Intermittent CKP sensor failure, loose connector, wiring corrosion, tone ring issue | All OBD-II (1996+) |
| P0340 | Camshaft Position Sensor Circuit Malfunction | Failed CMP sensor, wiring damage, timing chain stretch, connector corrosion | All OBD-II (1996+) |
| P0341 | Camshaft Position Sensor Circuit Range / Performance | Failed CMP sensor, timing chain stretch, wiring issue, tone ring damage | All OBD-II (1996+) |
| P0420 | Catalyst System Efficiency Below Threshold (Bank 1) | Failed catalytic converter, faulty oxygen sensors, exhaust leaks, engine misfire damage | All OBD-II (1996+) |
| P0443 | Evaporative Emission Control System Purge Control Valve Circuit Malfunction | Failed purge valve solenoid, wiring issue, clogged EVAP lines, connector corrosion | All OBD-II (1996+) |
| P0455 | Evaporative Emission System Gross Leak Detected | Loose or missing gas cap, cracked fuel tank, damaged EVAP lines, failed charcoal canister | All OBD-II (1996+) |
| P0456 | Evaporative Emissions System Small Leak Detected | Loose gas cap, small EVAP line leak, failed purge valve, charcoal canister issue | All OBD-II (1996+) |
| P0497 | Evaporative Emission System Low Purge Flow | Restricted purge valve or vapor lines, failed canister purge valve, clogged EVAP lines | 8th–11th gen |
| P0498 | Evaporative Emission System Vent Control Circuit Low | Failed vent valve solenoid, wiring issue, clogged vent line, connector corrosion | 8th–11th gen |
| P0507 | Idle Control System RPM Higher Than Expected | Vacuum leak, failed IAC valve, TPS sensor issue, intake manifold leak, carbon buildup | All OBD-II (1996+) |
| P0560 | System Voltage Malfunction | Failed alternator, weak battery, wiring issue, corroded battery terminals, PCM problem | All OBD-II (1996+) |
| P0730 | Incorrect Gear Ratio | Transmission fluid low, failed transmission solenoid, wiring issue, internal transmission damage | All OBD-II (1996+) |
| P0740 | Torque Converter Clutch Circuit Malfunction | Failed torque converter solenoid, transmission fluid issue, wiring problem, internal transmission damage | All OBD-II (1996+) |
| P0087 | Fuel Rail / System Pressure Too Low | Failed fuel pump, clogged fuel filter, fuel pressure regulator issue, leaking injector | 10th–11th gen (DI engines) |
| P0299 | Turbo / Supercharger Underboost | Boost leak, failed turbo, wastegate issue, intercooler leak, wiring problem (turbo models) | 10th–11th gen (turbo models) |
| P1361 / P1362 | Camshaft Position Sensor / TDC Sensor Circuit Malfunction | Failed CMP/TDC sensor, wiring issue, timing chain stretch (R18), connector corrosion | 6th–9th gen (D, B, R18, K engines) |
| P1456 | EVAP Control System Leak Detected (Fuel Tank) | Loose, damaged, or missing gas cap, fuel tank vapor line leak, cracked fuel tank | 6th–9th gen |
| P1457 | EVAP Control System Leak Detected (Canister) | Damaged charcoal canister, cracked EVAP lines, failed vent valve, canister seal leak | 6th–9th gen |
| P2646 / P2647 / P2648 / P2649 | Rocker Arm Oil Pressure Switch Circuit (Intake / Exhaust) | Low oil pressure, failed oil pressure switch, wiring issue, timing chain stretch (K20/K24) | 7th–11th gen (K-series engines) |
| P0685 / P0686 | Engine Control Module (ECM) / PCM Power Control Circuit | Failed main relay, wiring issue, blown fuse, corroded connectors, PCM problem | All OBD-II (1996+) |