Civic OBD2 Codes: Your Comprehensive Guide to Honda Diagnostic Trouble Codes

Decoding your Honda Civic’s check engine light can seem daunting, but understanding OBD2 codes is the first step to diagnosing and resolving car issues. As a Honda Civic owner, encountering a check engine light can be concerning. Fortunately, modern vehicles like the Honda Civic are equipped with an On-Board Diagnostic system (OBD2) that helps pinpoint potential problems. When your Civic’s check engine light illuminates, the system stores a diagnostic trouble code (DTC) – also known as an OBD2 code – which provides valuable clues about the nature of the malfunction. This guide provides a comprehensive list of Civic Obd2 Codes to help you understand what your car is trying to tell you. Let’s dive into the world of Civic OBD2 codes and empower you with the knowledge to keep your Honda running smoothly.

Understanding Common Civic OBD2 Codes

OBD2 codes are standardized across the automotive industry, but specific codes can relate to common issues in Honda Civics. This list, derived from Honda Service Bulletin #03-020, outlines a wide range of potential OBD2 codes you might encounter in your Civic. Understanding these codes is crucial for effective vehicle maintenance and repair.

P0010-P0099: Fuel and Air Metering and Auxiliary Emission Controls

P0010 Variable Valve Timing Control (VTC) Oil Control Solenoid Valve Malfunction: This code indicates a problem with the VTC oil control solenoid valve, which is crucial for variable valve timing in your Civic’s engine.
P0011 Variable Valve Timing Control (VTC) System Malfunction: A more general VTC system malfunction, which could stem from issues with the solenoid, timing chain, or oil pressure.
P0101 Mass Airflow (MAF) Sensor Range/Performance Problem: The MAF sensor measures the amount of air entering the engine. This code suggests the sensor is reading outside of its expected range or is not performing correctly.
P0102 Mass Airflow (MAF) Sensor Circuit Low Voltage: Indicates a low voltage signal in the MAF sensor circuit, potentially due to wiring issues or a faulty sensor.
P0103 Mass Airflow (MAF) Sensor Circuit High Voltage: Conversely, this points to a high voltage signal, suggesting a different electrical problem in the MAF sensor circuit.
P0106 Manifold Absolute Pressure (MAP) Sensor Range/Performance Problem: The MAP sensor measures pressure in the intake manifold. This code indicates the sensor is reading outside the expected range or is malfunctioning.
P0107 Manifold Absolute Pressure (MAP) Sensor Circuit Low Voltage: A low voltage reading in the MAP sensor circuit, possibly due to wiring or sensor failure.
P0108 Manifold Absolute Pressure (MAP) Sensor Circuit High Voltage: High voltage in the MAP sensor circuit, indicating an electrical issue.
P0111 Intake Air Temperature (IAT) Sensor Circuit Range/Performance Problem: The IAT sensor measures the temperature of the air entering the engine. This code suggests the sensor is reading outside its expected range.
P0112 Intake Air Temperature (IAT) Sensor Circuit Low Voltage: Low voltage signal in the IAT sensor circuit, potentially from wiring or a faulty sensor.
P0113 Intake Air Temperature (IAT) Sensor Circuit High Voltage: High voltage signal in the IAT sensor circuit, indicating an electrical problem.
P0116 Engine Coolant Temperature (ECT) Sensor Circuit Range/Performance Problem: The ECT sensor monitors engine coolant temperature. This code suggests the sensor is reading outside the expected range.
P0117 Engine Coolant Temperature (ECT) Sensor Circuit Low Input: Low input signal from the ECT sensor, possibly due to a short circuit or sensor failure.
P0118 Engine Coolant Temperature (ECT) Sensor Circuit High Input: High input signal from the ECT sensor, indicating an open circuit or sensor issue.
P0122 Throttle Position (TP) Sensor Circuit Low Input: The TP sensor monitors the throttle valve position. Low input signal suggests a potential short circuit or sensor problem.
P0123 Throttle Position (TP) Sensor Circuit High Input: High input signal from the TP sensor, possibly due to an open circuit or sensor malfunction.
P0125 Engine Coolant Temperature (ECT) Sensor Slow Response: Indicates the ECT sensor is not responding to temperature changes quickly enough, which can affect engine management.
P0128 Cooling System Malfunction: A general cooling system malfunction, which could involve the thermostat, radiator, coolant level, or other components.

P0130-P0199: Oxygen Sensors and Fuel System

P0131 Primary Heated Oxygen Sensor (Primary HO2S) (Sensor 1) Circuit Low Voltage: Low voltage reading from the primary oxygen sensor (sensor 1), which monitors exhaust gases before the catalytic converter.
P0132 Primary Heated Oxygen Sensor (Primary HO2S) (Sensor 1) Circuit High Voltage: High voltage reading from the primary oxygen sensor (sensor 1), indicating a potential electrical issue.
P0133 Rear Air/Fuel Ratio (A/F) Sensor (Bank 1, Sensor 1) Circuit Slow Response: Slow response from the rear air/fuel ratio sensor (sensor 1), which is related to fuel mixture control.
P0134 Air/Fuel Ratio (A/F) Sensor (Sensor 1) No Activity Detected: No signal detected from the air/fuel ratio sensor (sensor 1), suggesting a sensor failure or wiring problem.
P0135 Primary Heated Oxygen Sensor (Primary HO2S) (Sensor 1) Heater Circuit Malfunction: Malfunction in the heater circuit of the primary oxygen sensor (sensor 1), which is necessary for the sensor to function correctly.
P0137 Secondary Heated Oxygen Sensor (Secondary HO2S) Circuit Low Voltage: Low voltage reading from the secondary oxygen sensor, located after the catalytic converter, used to monitor catalytic converter efficiency.
P0138 Secondary Heated Oxygen Sensor (Secondary HO2S) Circuit High Voltage: High voltage reading from the secondary oxygen sensor, indicating an electrical problem.
P0139 Secondary Heated Oxygen Sensor (Secondary HO2S) Slow Response: Slow response from the secondary oxygen sensor, which can affect emissions monitoring.
P0141 Secondary Heated Oxygen Sensor (Secondary HO2S) (Sensor 2) Heater Circuit Malfunction: Heater circuit malfunction in the secondary oxygen sensor (sensor 2).
P0143 Third Heated Oxygen Sensor (Third HO2S) (Sensor 3) Circuit Low Voltage: Low voltage from a third oxygen sensor (sensor 3), if your Civic is equipped with one, usually for advanced emissions control.
P0144 Third Heated Oxygen Sensor (Third HO2S) (Sensor 3) Circuit High Voltage: High voltage from the third oxygen sensor (sensor 3).
P0145 Third Heated Oxygen Sensor (Third HO2S) (Sensor 3) Circuit Slow Response: Slow response from the third oxygen sensor (sensor 3).
P0147 Third Heated Oxygen Sensor (Third HO2S) (Sensor 3) Heater Circuit Malfunction: Heater circuit malfunction in the third oxygen sensor (sensor 3).
P0153 Front Air/Fuel Ratio (A/F) Sensor (Bank 2, Sensor 1) Circuit Slow Response: Slow response from the front air/fuel ratio sensor on Bank 2 (if applicable to your Civic engine type).
P0154 Front Air/Fuel Ratio (A/F) Sensor (Bank 2, Sensor 1) Heater System Malfunction: Heater system malfunction for the front air/fuel ratio sensor on Bank 2.
P0155 Front Air/Fuel Ratio (A/F) Sensor (Bank 2, Sensor 1) Heater Circuit Malfunction: Heater circuit malfunction for the front air/fuel ratio sensor on Bank 2.
P0157 Front Secondary Heated Oxygen Sensor (Secondary HO2S) (Bank 2, Sensor 2) Circuit Low Voltage: Low voltage from the front secondary oxygen sensor on Bank 2.
P0158 Front Secondary Heated Oxygen Sensor (Secondary HO2S) (Bank 2, Sensor 2) Circuit High Voltage: High voltage from the front secondary oxygen sensor on Bank 2.
P0159 Front Secondary Heated Oxygen Sensor (Secondary HO2S) (Bank 2, Sensor 2) Circuit Slow Response: Slow response from the front secondary oxygen sensor on Bank 2.
P0161 Front Secondary Heated Oxygen Sensor (Secondary HO2S) (Bank 2, Sensor 2) Heater Circuit Malfunction: Heater circuit malfunction for the front secondary oxygen sensor on Bank 2.
P0171 Fuel System Too Lean: Indicates the engine is running lean, meaning there is too much air and not enough fuel in the fuel mixture.
P0172 Fuel System Too Rich: Conversely, this indicates the engine is running rich, with too much fuel and not enough air.
P0174 Front Bank (Bank 2) Fuel System Too Lean: Fuel system lean condition specifically on Bank 2 of the engine.
P0175 Front Bank (Bank 2) Fuel System Too Rich: Fuel system rich condition on Bank 2.
P0191 Fuel Pressure Sensor Range/Performance Problem: Issue with the fuel pressure sensor reading outside of its expected range or malfunctioning.
P0192 Fuel Pressure Sensor Circuit Low Voltage: Low voltage in the fuel pressure sensor circuit.
P0193 Fuel Pressure Sensor Circuit High Voltage: High voltage in the fuel pressure sensor circuit.
P0196 EOT Sensor/Range Performance Problem: Problem with the Engine Oil Temperature (EOT) sensor range or performance.
P0197 EOT Sensor Circuit Low Voltage: Low voltage in the EOT sensor circuit.
P0198 EOT Sensor Circuit High Voltage: High voltage in the EOT sensor circuit.

P0200-P0299: Injector Circuit and Misfire Detection

P0222 Throttle Position (TP) Sensor 2 Circuit Low Voltage: Low voltage in the circuit for Throttle Position Sensor 2 (if equipped).
P0223 Throttle Position (TP) Sensor 2 Circuit High Voltage: High voltage in the circuit for Throttle Position Sensor 2.
P0300 Random Misfire: Indicates random misfires are occurring across multiple cylinders.
P0301 No. 1 Cylinder Misfire: Misfire detected specifically in cylinder number 1.
P0302 No. 2 Cylinder Misfire: Misfire in cylinder number 2.
P0303 No. 3 Cylinder Misfire: Misfire in cylinder number 3.
P0304 No. 4 Cylinder Misfire: Misfire in cylinder number 4.
P0305 No. 5 Cylinder Misfire: Misfire in cylinder number 5 (for engines with 5 or more cylinders).
P0306 No. 6 Cylinder Misfire: Misfire in cylinder number 6 (for engines with 6 or more cylinders).
P0325 Knock Sensor Circuit Malfunction: Malfunction in the knock sensor circuit, which detects engine knocking or detonation.

P0300-P0399: Ignition System or Misfire

P0335 Crankshaft Position (CKP) Sensor Circuit No Signal: No signal from the Crankshaft Position (CKP) sensor, which is vital for engine timing and operation.
P0336 P0339 Crankshaft Position (CKP) Sensor Circuit Intermittent Interruption: Intermittent signal interruption from the CKP sensor.
P0340 Camshaft Position (CMP) Sensor No Signal: No signal from the Camshaft Position (CMP) sensor, important for valve timing and fuel injection.
P0341 Camshaft Position (CMP) Sensor A Intermittent Interruption: Intermittent signal from CMP sensor A.
P0341 Variable Valve Timing Control (VTC) Phase Gap: Discrepancy in the VTC phase, related to camshaft timing.
P0344 Camshaft Position (CMP) Sensor Intermittent Interruption: General intermittent signal issue with the CMP sensor.
P0365 Camshaft Position (CMP) Sensor B No Signal: No signal from CMP sensor B (if equipped).
P0366 P0369 Camshaft Position (CMP) Sensor B Intermittent Interruption: Intermittent signal from CMP sensor B.
P0385 Crankshaft Position (CKP) Sensor B No Signal: No signal from CKP sensor B (if equipped).
P0389 Crankshaft Position (CKP) Sensor B Intermittent Interruption: Intermittent signal from CKP sensor B.

P0400-P0499: Auxiliary Emission Controls

P0401 Exhaust Gas Recirculation (EGR) Insufficient Flow: Insufficient flow in the Exhaust Gas Recirculation (EGR) system, which reduces NOx emissions.
P0404 Exhaust Gas Recirculation (EGR) Control Circuit Range/Performance Problem: EGR control circuit issue, sensor reading outside of expected range or performance problems.
P0406 Exhaust Gas Recirculation (EGR) Valve Position Sensor Circuit High Voltage: High voltage in the EGR valve position sensor circuit.
P0410 Air Pump Circuit Malfunction: Malfunction in the air pump circuit, part of the secondary air injection system for emissions.
P0411 Secondary Air Injection System Incorrect Flow: Incorrect flow in the secondary air injection system.
P0420 Catalyst System Efficiency Below Threshold: Catalytic converter efficiency is below the required threshold, indicating potential catalytic converter failure.
P0430 Front Bank Catalyst System Efficiency Below Threshold (Bank 2): Catalytic converter efficiency below threshold on Bank 2.
P0441 Evaporative Emission (EVAP) Control System Incorrect Purge Flow: Incorrect purge flow in the Evaporative Emission (EVAP) control system, which manages fuel vapor emissions.
P0442 Evaporative Emission (EVAP) System Small Leak Detected: Small leak detected in the EVAP system.
P0443 Evaporative Emission (EVAP) Canister Purge Valve Circuit Malfunction: Malfunction in the EVAP canister purge valve circuit.
P0451 Fuel Tank Pressure (FTP) Sensor Range/Performance Problem: Fuel Tank Pressure (FTP) sensor reading outside of expected range or performance issues.
P0452 Fuel Tank Pressure (FTP) Sensor Circuit Low Voltage: Low voltage in the FTP sensor circuit.
P0453 Fuel Tank Pressure (FTP) Sensor Circuit High Voltage: High voltage in the FTP sensor circuit.
P0456 Evaporative Emission (EVAP) System Very Small Leak Detected: Very small leak detected in the EVAP system.
P0457 Evaporative Emission (EVAP) System Leak Detected Fuel Fill Cap Loose/Off: EVAP system leak likely due to a loose or missing fuel cap.
P0461 Fuel Gauge Sending Unit Range/Performance Problem: Fuel gauge sending unit reading outside of expected range or performance issues.
P0462 Fuel Gauge Sending Unit Circuit Low Voltage: Low voltage in the fuel gauge sending unit circuit.
P0463 Fuel Gauge Sending Unit Circuit High Voltage: High voltage in the fuel gauge sending unit circuit.
P0496 Evaporative Emission (EVAP) System High Purge Flow: High purge flow in the EVAP system.
P0497 Evaporative Emission (EVAP) System Low Purge Flow: Low purge flow in the EVAP system.
P0498 Evaporative Emission (EVAP) Canister Vent Shut Valve Control Circuit Low Voltage: Low voltage in the EVAP canister vent shut valve control circuit.
P0499 Evaporative Emission (EVAP) Canister Vent Shut Valve Control Circuit High Voltage: High voltage in the EVAP canister vent shut valve control circuit.

P0500-P0599: Vehicle Speed, Idle Control, and Auxiliary Inputs

P0500 Vehicle Speed Sensor (VSS) Circuit Malfunction: Malfunction in the Vehicle Speed Sensor (VSS) circuit, affecting speedometer and potentially transmission operation.
P0501 Vehicle Speed Sensor (VSS) Range/Peformance Problem: VSS reading outside of expected range or performance issues.
P0505 Idle Control System Malfunction: General malfunction in the idle control system.
P0506 Idle Control System RPM Lower Than Expected: Idle RPM is lower than the target RPM.
P0507 Idle Control System RPM Higher Than Expected: Idle RPM is higher than the target RPM.
P0511 Idle Air Control (IAC) Valve Circuit Malfunction: Malfunction in the Idle Air Control (IAC) valve circuit, which regulates idle speed.
P0521 EOP Sensor Range/Performance Problem: Engine Oil Pressure (EOP) sensor reading outside of expected range or performance issues.
P0522 EOP Sensor Circuit Low Voltage: Low voltage in the EOP sensor circuit.
P0523 EOP Sensor Circuit High Voltage: High voltage in the EOP sensor circuit.
P0560 ECM Back-up Circuit Low Voltage: Low voltage in the Engine Control Module (ECM) back-up circuit.
P0563 Engine Control Module (ECM)/Powertrain Control Module (PCM) Power Source Circuit Unexpected Voltage: Unexpected voltage in the ECM/PCM power source circuit.

P0600-P0699: Computer Output Circuit Monitoring

P0600 Multiplex Control System Troubleshooting: General issue with the multiplex control system, which handles communication between various modules.
P0603 ECM/PCM Internal Control Module Keep Alive Memory (KAM) Error: Error in the ECM/PCM’s Keep Alive Memory (KAM), which stores learned information.
P0606 ECM/PCM Processor Malfunction: Malfunction in the ECM/PCM processor itself.
P0661 Intake Manifold Runner Control (IMRC) Valve Position Sensor Circuit Low Voltage: Low voltage in the IMRC valve position sensor circuit, which controls airflow into the intake manifold.
P0662 Intake Manifold Runner Control (IMRC) Valve Position Sensor Circuit High Voltage: High voltage in the IMRC valve position sensor circuit.
P0685 ECM/PCM Power Relay Control Circuit Malfunction: Malfunction in the ECM/PCM power relay control circuit.

P0700-P0999: Transmission

P0700 Automatic Transmission Control System: General issue with the automatic transmission control system.
P0705 Short in Transmission Range Switch Circuit (Multiple Shift-position Input): Short circuit in the transmission range switch circuit, indicating conflicting gear position signals.
P0706 Open in Transmission Range Switch Circuit: Open circuit in the transmission range switch circuit.
P0710 P0711 Problem in ATF Temperature Sensor Circuit: Problem with the Automatic Transmission Fluid (ATF) temperature sensor circuit.
P0712 Short in ATF Temperature Sensor Circuit: Short circuit in the ATF temperature sensor circuit.
P0713 Open in ATF Temperature Sensor Circuit: Open circuit in the ATF temperature sensor circuit.
P0715 P0716 Problem in Mainshaft Speed Sensor Circuit: Problem with the mainshaft speed sensor circuit in the transmission.
P0717 Problem in Mainshaft Speed Sensor Circuit (No Signal Input): No signal from the mainshaft speed sensor.
P0718 Mainshaft Speed Sensor Intermittent Failure: Intermittent failure of the mainshaft speed sensor.
P0720 Countershaft Speed Sensor Circuit Malfunction: Malfunction in the countershaft speed sensor circuit.
P0720 P0721 Problem in Countershaft Speed Sensor Circuit: Problem with the countershaft speed sensor circuit.
P0722 Problem in Countershaft Speed Sensor Circuit (No Signal Input): No signal from the countershaft speed sensor.
P0723 Countershaft Speed Sensor Intermittent Failure: Intermittent failure of the countershaft speed sensor.
P0725 Engine Speed Input Circuit Malfunction: Malfunction in the engine speed input circuit to the transmission control system.
P0730 Problem in Shift Control System: General problem in the transmission shift control system.
P0731 Problem in 1st Clutch and 1st Clutch Hydraulic Circuit: Problem with the 1st clutch or its hydraulic circuit.
P0732 Problem in 2nd Clutch and 2nd Clutch Hydraulic Circuit: Problem with the 2nd clutch or its hydraulic circuit.
P0733 Problem in 3rd Clutch and 3rd Clutch Hydraulic Circuit: Problem with the 3rd clutch or its hydraulic circuit.
P0734 Problem in 4th Clutch and 4th Clutch Hydraulic Clutch: Problem with the 4th clutch or its hydraulic circuit.
P0735 Problem in 5th Clutch and 5th Clutch Hydraulic Circuit: Problem with the 5th clutch or its hydraulic circuit (if applicable).
P0740 Problem in Lock-up Control System: Problem with the torque converter lock-up control system.
P0741 Torque Converter Clutch Hydraulic Clutch Stuck OFF: Torque converter clutch is stuck in the OFF position.
P0743 Problem in Torque Converter Clutch Solenoid Valve Circuit: Malfunction in the torque converter clutch solenoid valve circuit.
P0745 Problem in Hydraulic Control System of A/T Clutch Pressure Control Solenoid Valve A Circuit: Problem in the hydraulic control system for clutch pressure control solenoid valve A.
P0746 A/T Clutch Pressure Control Solenoid Valve A Stuck OFF: Clutch pressure control solenoid valve A is stuck in the OFF position.
P0747 A/T Clutch Pressure Control Solenoid Valve A Stuck ON: Clutch pressure control solenoid valve A is stuck in the ON position.
P0748 Problem in A/T Clutch Pressure Control Solenoid Valve A Circuit: Malfunction in the clutch pressure control solenoid valve A circuit.
P0750 Problem in Hydraulic Control System of Shift Solenoid Valve A Circuit: Problem in the hydraulic control system for shift solenoid valve A.
P0751 Shift Solenoid Valve A Stuck OFF: Shift solenoid valve A is stuck in the OFF position.
P0752 Shift Solenoid Valve A Stuck ON: Shift solenoid valve A is stuck in the ON position.
P0753 Problem in Shift Solenoid Valve A Circuit: Malfunction in the shift solenoid valve A circuit.
P0756 Shift Solenoid Valve B Stuck OFF: Shift solenoid valve B is stuck in the OFF position.
P0757 Shift Solenoid Valve B Stuck ON: Shift solenoid valve B is stuck in the ON position.
P0758 Problem in Shift Solenoid Valve B Circuit: Malfunction in the shift solenoid valve B circuit.
P0761 Shift Solenoid Valve C Stuck OFF: Shift solenoid valve C is stuck in the OFF position.
P0762 Shift Solenoid Valve C Stuck ON: Shift solenoid valve C is stuck in the ON position.
P0763 Problem in Shift Solenoid Valve C Circuit: Malfunction in the shift solenoid valve C circuit.
P0771 Shift Solenoid Valve E Stuck OFF: Shift solenoid valve E is stuck in the OFF position (if applicable).
P0773 Problem in Shift Solenoid Valve E Circuit: Malfunction in the shift solenoid valve E circuit (if applicable).
P0775 Problem in the Hydraulic Control System of A/T Clutch Pressure Control Solenoid Valve B Circuit: Problem in the hydraulic control system for clutch pressure control solenoid valve B.
P0776 A/T Clutch Pressure Control Solenoid Valve B Stuck OFF: Clutch pressure control solenoid valve B is stuck in the OFF position.
P0777 A/T Clutch Pressure Control Solenoid Valve B Stuck ON: Clutch pressure control solenoid valve B is stuck in the ON position.
P0778 Problem in A/T Clutch Pressure Control Solenoid Valve B Circuit: Malfunction in the clutch pressure control solenoid valve B circuit.
P0780 Problem in Shift Control System: General problem in the shift control system.
P0795 Problem in Hydraulic Control System of A/T Clutch Pressure Control Solenoid Valve C Circuit: Problem in the hydraulic control system for clutch pressure control solenoid valve C.
P0796 A/T Clutch Pressure Control Solenoid Valve C Stuck OFF: Clutch pressure control solenoid valve C is stuck in the OFF position.
P0797 A/T Clutch Pressure Control Solenoid Valve C Stuck ON: Clutch pressure control solenoid valve C is stuck in the ON position.
P0798 Problem in A/T Clutch Pressure Control Solenoid Valve C Ciruit: Malfunction in the clutch pressure control solenoid valve C circuit.
P0812 Open in Transmission Range Switch ATP RVS Switch Circuit: Open circuit in the transmission range switch ATP RVS (Reverse) switch circuit.
P0842 Short in 2nd Clutch Transmission Fluid Pressure Switch Clutch, or 2nd Clutch Transmission Fluid Pressure Switch (Clutch) Stuck ON: Short circuit or stuck ON condition in the 2nd clutch transmission fluid pressure switch.
P0843 Open in 2nd Clutch Transmission Fluid Pressure Switch Circuit, or 2nd Clutch Transmission Fluid Pressure Switch Stuck OFF: Open circuit or stuck OFF condition in the 2nd clutch transmission fluid pressure switch.
P0845 Problem in 3rd Clutch Pressure Switch Circuit: Problem in the 3rd clutch pressure switch circuit.
P0847 Short in 3rd Clutch Transmission Fluid Pressure Switch Circuit, or 3rd Clutch Transmission Fluid Pressure Switch Stuck ON: Short circuit or stuck ON condition in the 3rd clutch transmission fluid pressure switch.
P0848 Open in 3rd Clutch Transmission Fluid Pressure Switch Circuit, or 3rd Clutch Transmission Fluid Pressure Switch Stuck OFF: Open circuit or stuck OFF condition in the 3rd clutch transmission fluid pressure switch.
P0872 Short in 4th Clutch Transmission Fluid Pressure Switch Circuit, or 4th Clutch Transmission Fluid Pressure Switch Stuck ON: Short circuit or stuck ON condition in the 4th clutch transmission fluid pressure switch.
P0873 Open in 4th Clutch Transmission Fluid Pressure Switch Circuit, or 4th Clutch Transmission Fluid Pressure Switch Stuck OFF: Open circuit or stuck OFF condition in the 4th clutch transmission fluid pressure switch.
P0962 Problem in A/T Clutch Pressure Control Solenoid Valve A Circuit: Problem in the clutch pressure control solenoid valve A circuit.
P0963 Problem in A/T Clutch Pressure Control Solenoid Valve A: Problem with clutch pressure control solenoid valve A itself.
P0966 Problem in A/T Clutch Pressure Control Solenoid Valve B Circuit: Problem in the clutch pressure control solenoid valve B circuit.
P0967 Problem in A/T Clutch Pressure Control Solenoid Valve B: Problem with clutch pressure control solenoid valve B itself.
P0970 Problem in A/T Clutch Pressure Control Solenoid Valve C Circuit: Problem in the clutch pressure control solenoid valve C circuit.
P0971 Problem in A/T Clutch Pressure Control Solenoid Valve C: Problem with clutch pressure control solenoid valve C itself.
P0973 Short in Shift Solenoid Valve A Circuit: Short circuit in shift solenoid valve A circuit.
P0974 Open in Shift Solenoid Valve A Circuit: Open circuit in shift solenoid valve A circuit.
P0976 Short in Shift Solenoid Valve B Circuit: Short circuit in shift solenoid valve B circuit.
P0977 Open in Shift Solenoid Valve B Circuit: Open circuit in shift solenoid valve B circuit.
P0979 Short in Shift Solenoid Valve C Circuit: Short circuit in shift solenoid valve C circuit.
P0980 Open in Shift Solenoid Valve C Circuit: Open circuit in shift solenoid valve C circuit.
P0982 Short in Shift Solenoid Valve D Circuit: Short circuit in shift solenoid valve D circuit (if applicable).
P0983 Open in Shift Solenoid Valve D Circuit: Open circuit in shift solenoid valve D circuit (if applicable).
P0985 Short in Shift Solenoid Valve E Circuit: Short circuit in shift solenoid valve E circuit (if applicable).
P0986 Open in Shift Solenoid Valve E Circuit: Open circuit in shift solenoid valve E circuit (if applicable).

P1000-P1099 & P1100-P1199: Manufacturer Specific and Fuel/Air Metering

P1020 Valve Pause System Stuck Off: Valve Pause System is stuck in the OFF position (likely manufacturer-specific).
P1021 Valve Pause System Stuck On: Valve Pause System is stuck in the ON position.
P1025 Valve Pause System Sticking Off: Valve Pause System is sticking in the OFF position.
P1026 Valve Pause System Sticking On: Valve Pause System is sticking in the ON position.
P1077 Intake Manifold Runner Control (IMRC) System Malfunction (Low rpm): IMRC system malfunction at low RPM.
P1078 Intake Mainfold Runner Control (IMRC) System Malfunction (High rpm): IMRC system malfunction at high RPM.
P1106 Barometric Pressure (BARO) Sensor Circuit Range/Performance Problem: Barometric Pressure (BARO) sensor reading outside of expected range or performance issues.
P1107 Barometric Pressure (BARO) Sensor Circuit Low Voltage: Low voltage in the BARO sensor circuit.
P1108 Barometric Pressure (BARO) Sensor Circuit High Voltage: High voltage in the BARO sensor circuit.
P1121 Throttle Position (TP) Sensor Lower Than Expected: TP sensor reading lower than expected.
P1122 Throttle Position (TP) Sensor Higher Than Expected: TP sensor reading higher than expected.
P1128 Manifold Absolute Pressure (MAP) Sensor Circuit Lower Than Expected: MAP sensor reading lower than expected.
P1129 Manifold Absolute Pressure (MAP) Sensor Circuit Higher Than Expected: MAP sensor reading higher than expected.
P1130 Demand for Changing Both Secondary Heated Oxygen Sensor (Secondary HO2S) (Sensor 2) and Third Heated Oxygen Sensor (Third HO2S) (Sensor 3): Request to change both secondary and third oxygen sensors.
P1149 Air/Fuel Ratio (A/F) Sensor (Sensor 1) Range/Performance Problem: Air/Fuel Ratio sensor (sensor 1) reading outside of expected range or performance issues.
P1149 Air/Fuel Ratio Sensor (Sensor 1) Circuit Lean Range: Air/Fuel Ratio sensor (sensor 1) indicating a lean condition.
P1157 Air/Fuel Ratio (A/F) Sensor (Sensor 1) AFS Line High Voltage: High voltage on the AFS line of the Air/Fuel Ratio sensor (sensor 1).
P1157 Air/Fuel Ratio (A/F) Sensor (Sensor 1) Circuit High Voltage: High voltage in the Air/Fuel Ratio sensor (sensor 1) circuit.
P1157 Air/Fuel Ratio (A/F) Sensor (Sensor 1) Range/Performance Problem: Repeated code, likely a typo in the source.
P1158 Air/Fuel Ratio (A/F) Sensor (Sensor 1) AFS- Terminal Low Voltage: Low voltage on the AFS- terminal of the Air/Fuel Ratio sensor (sensor 1).
P1159 Air/Fuel Ratio (A/F) Sensor (Sensor 1) AFS+ Terminal Low Voltage: Low voltage on the AFS+ terminal of the Air/Fuel Ratio sensor (sensor 1).
P1162 Air/Fuel Ratio (A/F) Sensor (Sensor 1) Slow Response: Slow response from the Air/Fuel Ratio sensor (sensor 1).
P1163 Air/Fuel Ratio (A/F) Sensor (Sensor 1) Slow Response: Repeated code, likely a typo in the source.
P1163 Air/Fuel Ratio Sensor (Sensor 1) Slow Response: Repeated code, likely a typo in the source.
P1164 Air/Fuel Ratio (A/F) Sensor (Sensor 1) Range/Performance Problem: Repeated code, likely a typo in the source.
P1164 Air/Fuel Ratio (AF) Sensor (Sensor 1) Circuit Range/Performance: Repeated code, likely a typo in the source.
P1165 Air/Fuel Ratio (A/F) Sensor (Sensor 1) Range/Performance Problem: Repeated code, likely a typo in the source.
P1165 Air/Fuel Ratio Sensor (Sensor 1) Circuit Range/Performance: Repeated code, likely a typo in the source.
P1166 Air/Fuel Ratio (A/F) Sensor (Sensor 1) Heater System Electrical Problem: Electrical problem in the heater system of the Air/Fuel Ratio sensor (sensor 1).
P1166 Heated Oxgen Sensor Sensor1 (Primary HO2S) Heater Circuit Malfunction: Repeated code, likely a typo in the source.
P1167 Air/Fuel Ratio (A/F) Sensor (Sensor 1) Heater System Malfunction: Heater system malfunction in the Air/Fuel Ratio sensor (sensor 1).
P1167 Heated Oxygen Sensor Sensor1 (Primary LAF HO2S) Heater System Malfunction: Repeated code, likely a typo in the source.
P1168 Air/Fuel Ratio (A/F) Sensor (Sensor 1) LABEL Low Voltage: Low voltage on the LABEL line of the Air/Fuel Ratio sensor (sensor 1).
P1169 Air/Fuel Ratio (A/F) Sensor (Sensor 1) LABEL High Voltage: High voltage on the LABEL line of the Air/Fuel Ratio sensor (sensor 1).
P1182 Fuel Temperature Sensor Circuit Low Voltage: Low voltage in the fuel temperature sensor circuit.
P1183 Fuel Temperature Sensor Circuit High Voltage: High voltage in the fuel temperature sensor circuit.

P1200-P1299: VTEC and Electrical Load Detector

P1253 P1259 VTEC System Malfunction: General malfunction in the Variable Valve Timing and Lift Electronic Control (VTEC) system.
P1297 Electric Load Detector (ELD) Circuit Low Voltage: Low voltage in the Electric Load Detector (ELD) circuit, which monitors electrical load on the system.
P1298 Electric Load Detector (ELD) Circuit High Voltage: High voltage in the ELD circuit.

P1300-P1399: Misfire and Crank/Cam Sensors

P1300 Random Misfire: Repeated code, likely a typo in the source.
P1324 Knock Sensor Power Source Circuit Low Voltage: Low voltage in the knock sensor power source circuit.
P1336 Engine Speed (RPM) Fluctuation Sensor Intermittent Interruption: Intermittent signal from the engine speed fluctuation sensor.
P1337 Engine Speed (RPM) Fluctuation Sensor No Signal: No signal from the engine speed fluctuation sensor.
P1355 Front Ignition Coil Power Circuit Malfunction: Malfunction in the power circuit for the front ignition coil.
P1359 Crankshaft Position (CKP)/Top Dead Center (TDC) Sensor Circuit Malfunction: Malfunction in the CKP/TDC sensor circuit.
P1361 Camshaft Position (CMP) Sensor A (Top Dead Center (TDC) Sensor) Intermittent Interruption: Intermittent signal from CMP sensor A (TDC sensor).
P1361 Top Dead Center (TDC) Sensor Intermittent Interruption: Repeated code, likely a typo in the source.
P1362 Camshaft Position (CMP) Sensor A (Top Dead Center (TDC) Sensor) No Signal: No signal from CMP sensor A (TDC sensor).
P1362 Top Dead Center (TDC) Sensor No Signal: Repeated code, likely a typo in the source.
P1366 Camshaft Position (CMP) Sensor B (Top Dead Center (TDC) Sensor) Intermittent Interruption: Intermittent signal from CMP sensor B (TDC sensor).
P1366 Top Dead Center (TDC) Sensor 2 Intermittent Interruption: Repeated code, likely a typo in the source.
P1367 Camshaft Position (CMP) Sensor B (Top Dead Center (TDC) Sensor) No Signal: No signal from CMP sensor B (TDC sensor).
P1367 Top Dear Center (TDC) Sensor 2 No Signal: Repeated code, likely a typo in the source.
P1381 Cylinder Position (CYP) Sensor Intermittent Interruption: Intermittent signal from the Cylinder Position (CYP) sensor.
P1382 Cylinder Position (CYP) Sensor No Signal: No signal from the CYP sensor.

P1400-P1499: EGR, Air Pump, and EVAP System

P1410 Air Pump Malfunction: Malfunction in the air pump.
P1415 Air Pump Electric Current Sensor Circuit Low Voltage: Low voltage in the air pump electric current sensor circuit.
P1416 Air Pump Electric Current Sensor Circuit High Voltage: High voltage in the air pump electric current sensor circuit.
P1420 Nox Adsorptive Catalyst System Efficiency Below Threshold: Efficiency of the NOx adsorptive catalyst system is below threshold.
P1438 Motor Drive Module (MDM) Overheating Signal Circuit: Overheating signal from the Motor Drive Module (MDM) circuit.
P1438 Motor Drive Module (MDM) Overheating: MDM overheating condition.
P1439 Motor Drive Module (MDM) Short Circuit Sensor Problem: Short circuit sensor problem in the MDM.
P1439 Motor Drive Module (MDM) Short Circuit: MDM short circuit condition.
P1440 IMA System Problem: Integrated Motor Assist (IMA) system problem (for hybrid models).
P1445 Bypass Control Problem: Problem with the bypass control system (likely EVAP or emissions related).
P1448 P1449 Battery Module Overheating: Battery module overheating (for hybrid models).
P1449 Battery Cell Overheating: Battery cell overheating (for hybrid models).
P1449 Battery Module Individual Voltage Input Deviation: Voltage deviation in individual battery modules (for hybrid models).
P1449 Battery Module Deterioration: Battery module deterioration (for hybrid models).
P1449 Battery Module Deviation: Repeated code, likely a typo in the source.
P1454 Fuel Tank Pressure (FTP) Sensor Range/Performance Problem: Repeated code, likely a typo in the source.
P1456 Evaporative Emissions (EVAP) Control System Leakage (Fuel Tank System): EVAP system leak specifically in the fuel tank system.
P1457 Evaporative Emissions (EVAP) Control System Leakage (EVAP Canister System): EVAP system leak in the EVAP canister system.
P1459 Evaporative Emission (EVAP) Purge Flow Switch Malfunction: Malfunction in the EVAP purge flow switch.
P1491 Exhaust Gas Recirculation (EGR) Valve Insufficient Lift: Insufficient lift of the Exhaust Gas Recirculation (EGR) valve.
P1486 Cooling System Malfunction: Repeated code, likely a typo in the source.
P1491 Exhaust Gas Recirculation (EGR) Valve Insufficient Lift: Repeated code, likely a typo in the source.
P1498 Exhaust Gas Recirculation (EGR) Valve Position Sensor Circuit High Voltage: High voltage in the EGR valve position sensor circuit.

P1500-P1599: Idle Control and Manufacturer Specific

P1505 Positive Crankcase Ventilation (PCV) Air Leakage: Air leak in the Positive Crankcase Ventilation (PCV) system.
P1508 P1519 Idle Air Control Valve (IACV) Circuit Malfunction: Malfunction in the Idle Air Control Valve (IACV) circuit.
P1509 Idle Air Control Valve (IACV) Circuit Failure: Failure in the IACV circuit.
P1522 Brake Booster Pressure Sensor Circuit Low Voltage: Low voltage in the brake booster pressure sensor circuit.
P1523 Brake Booster Pressure Sensor Circuit High Voltage: High voltage in the brake booster pressure sensor circuit.
P1524 Brake Booster Pressure Sensor Range/Performance Problem: Brake booster pressure sensor reading outside of expected range or performance issues.
P1541 Climate Control Unit Signal Circuit Low Voltage: Low voltage in the climate control unit signal circuit.
P1542 Climate Control Unit Signal Circuit High Voltage: High voltage in the climate control unit signal circuit.
P1565 Motor Commutation Signal Problem: Problem with the motor commutation signal (likely for hybrid models).
P1568 Battery Module Individual Voltage Input Problem: Repeated code, likely a typo in the source.
P1568 Battery Module Temperature Signal Circuit Problem: Battery module temperature signal circuit problem (for hybrid models).
P1568 Battery Cell Temperature Signal Circuit Problem: Battery cell temperature signal circuit problem (for hybrid models).
P1572 Motor Drive Module (MDM) Temperature Signal Circuit Low Input: Low input from the MDM temperature signal circuit.
P1572 Motor Drive Module (MDM) Temperature Signal Circuit High Input: High input from the MDM temperature signal circuit.
P1576 Motor Drive Module (MDM) Voltge Signal Circuit Low Input: Low input from the MDM voltage signal circuit.
P1577 High Voltage Detection Signal Circuit Problem: Problem with the high voltage detection signal circuit (likely for hybrid models).
P1580 Battery Current Circuit Problem: Battery current circuit problem (for hybrid models).
P1581 Motor Power Inverter (MPI) Module Current Signal Circuit Low Input: Low input from the MPI module current signal circuit.
P1581 Motor Power Inverter (MPI) Module Current Signal Circuit High Input: High input from the MPI module current signal circuit.
P1581 Motor Power Inverter (MPI) Module Current Signal Circuit Problem: Repeated code, likely a typo in the source.
P1582 Motor Current U Phase Signal Circuit Low Input: Low input from the motor current U phase signal circuit.
P1582 Motor Current U Phase Signal Circuit High Input: High input from the motor current U phase signal circuit.
P1583 Motor Current V Phase Signal Circuit Low Input: Low input from the motor current V phase signal circuit.
P1583 Motor Current V Phase Signal Circuit High Input: High input from the motor current V phase signal circuit.
P1584 Motor Current W Phase Signal Circuit Low Input: Low input from the motor current W phase signal circuit.
P1584 Motor Current W Phase Signal Circuit High Input: High input from the motor current W phase signal circuit.
P1585 Motor Current Signal Circuit Problem: Motor current signal circuit problem.
P1586 Motor Power Inverter (MPI) Module Current Signal/Battery Current Signal Circuit Problem: Problem with both MPI module current and battery current signal circuits.
P1607 Engine Control Module (ECM)/Powertrain Control Module (PCM) Internal Circuit Malfunction: Internal circuit malfunction within the ECM/PCM.
P1630 Transmission Control Module: General Transmission Control Module (TCM) issue.
P1635 Battery Condition Monitor (BCM) Module Proble: Battery Condition Monitor (BCM) module problem.
P1639 MOTB Signal Circuit Malfunction: Malfunction in the MOTB (Motor Throttle Body) signal circuit.
P1640 ACTTRQ Motor Torque Signal Circuit Low Input: Low input from the ACTTRQ (Actual Torque) motor torque signal circuit.
P1641 ACTTRQ Motor Torque Signal Circuit High Input: High input from the ACTTRQ motor torque signal circuit.
P1642 QBATT Battery Signal Circuit Low Input: Low input from the QBATT (Battery Current) signal circuit.
P1643 QBATT Battery Signal Circuit High Input: High input from the QBATT battery signal circuit.
P1644 MOTFSA Signal Malfunction: Malfunction in the MOTFSA (Motor Feedback Signal A) signal.
P1645 MOTFSB Signal Malfunction: Malfunction in the MOTFSB (Motor Feedback Signal B) signal.
P1646 MOTSTB Signal Malfunction: Malfunction in the MOTSTB (Motor Status B) signal.
P1647 Power Command Signal Circuit Low Input: Low input from the power command signal circuit.
P1647 Power Command Signal Circuit High Input: High input from the power command signal circuit.
P1647 Engine Torque Signal Circuit Low Input: Repeated code, likely a typo in the source.
P1647 Engine Torque Signal Circuit High Input: Repeated code, likely a typo in the source.
P1647 Mode Signal Circuit 1 Low Input: Repeated code, likely a typo in the source.
P1647 Mode Signal Circuit 1 High Input: Repeated code, likely a typo in the source.
P1647 Mode Signal Circuit 2 Problem: Repeated code, likely a typo in the source.
P1647 Engine Speed Signal Circuit Problem: Repeated code, likely a typo in the source.
P1648 Battery Condition Monitor (BCM) Module Communication Signal Circuit Problem: Communication signal circuit problem with the BCM module.
P1648 Motor Control Module (MCM) Communication Signal Circuit Problem: Communication signal circuit problem with the Motor Control Module (MCM).
P1655 CVT-FI TMA/TMB Signal Line Failure: Failure in the CVT-FI TMA/TMB signal line (Continuously Variable Transmission – Fuel Injection Turbine Meter A/B).
P1656 Problem in PCM-toVTM-4 Control Unit Communications Circuit: Communication circuit problem between the PCM and VTM-4 (Variable Torque Management 4-Wheel Drive) control unit.
P1660 A/T-FI Data Line Failure/TCM – ECM Halt: Data line failure between the Automatic Transmission – Fuel Injection system or TCM-ECM halt.
P1676 P1678 FPTDR Signal Line Failure: Failure in the FPTDR (Fuel Pump Transistor Drive Relay) signal line.
P1679 RSCD Signal Circuit Malfunction: Malfunction in the RSCD (Remote Starter Control Disable) signal circuit.
P1681 A/T FI Signal A Cicuit Low Voltage: Low voltage in the A/T FI Signal A circuit.
P1682 A/T FI Signal A Circuit High Voltage: High voltage in the A/T FI Signal A circuit.
P1683 Throttle Valve Default Position Spring Performance Problem: Performance problem with the throttle valve default position spring.
P1684 Throttle Valve Return Spring Performance Problem: Performance problem with the throttle valve return spring.
P1686 A/T FI Signal B Circuit Low Voltage: Low voltage in the A/T FI Signal B circuit.
P1687 A/T FI Signal B Circuit High Voltage: High voltage in the A/T FI Signal B circuit.

P1700-P1999: Transmission Continued

P1705 Short in Transmission Range Switch Circuit (More than one range position is on at the same time): Short circuit in the transmission range switch circuit with multiple gear positions active simultaneously.
P1706 Open in Transmission Range Switch Circuit: Repeated code, likely a typo in the source.
P1709 Problem Transmission Gear Selection Switch Circuit: Problem with the transmission gear selection switch circuit.
P1730 Problem in Shift Control System: Shift Solenoid Valve A and D Stuck OFF Shift Solenoid Valve B Stuck ON Shift Valves A, B, and D Stuck: Complex shift control system problem involving shift solenoid valves A, B, and D.
P1731 Problem in Shift Control System: Shift Solenoid Valve E Stuck ON Shift Valve E Stuck A/T Clutch Pressure Control Solenoid Valve A Stuck OFF: Complex shift control system problem involving shift solenoid valve E and clutch pressure control solenoid valve A.
P1732 Problem in Shift Control System: Shift Solenoid Valve B and C Stuck ON Shift Valves B and C Stuck: Complex shift control system problem involving shift solenoid valves B and C.
P1733 Problem in Shift Control System: Shift Solenoid Valve D Stuck ON Shift Valve D Stuck A/T Clutch Pressure Control Solenoid Valve C Stuck OFF: Complex shift control system problem involving shift solenoid valve D and clutch pressure control solenoid valve C.
P1734 Problem in Shift Control System: Shift Solenoid Valves B and C Stuck ON Shift Valves B and C Stuck: Repeated code, likely a typo in the source.
P1738 Problem in 2nd Clutch Pressure Switch Circuit: Problem in the 2nd clutch pressure switch circuit.
P1739 Problem in 3rd Clutch Pressure Switch Circuit: Problem in the 3rd clutch pressure switch circuit.
P1740 Problem in 4th Clutch Pressure Switch Circuit: Problem in the 4th clutch pressure switch circuit.
P1750 Mechanical Problem in Hydraulic Control System of A/T Clutch Pressure Control Solenoid Valve Assemblies A and B, or Problem in the Hydraulic Control System: Mechanical or hydraulic problem in the clutch pressure control solenoid valve assemblies A and B.
P1751 Mechanical Problem in Hydraulic Control System of Shift Solenoid Valve B and A/T Clutch Pressure Control Solenoid Valves A and B, or Problem in the Hydraulic Control System: Complex mechanical or hydraulic problem involving shift solenoid valve B and clutch pressure control solenoid valves A and B.
P1753 Problem in Torque Converter Clutch Solenoid Valve Circuit: Repeated code, likely a typo in the source.
P1751 P1768 Problem in Torque Converter Clutch Solenoid Valve B Circuit: Problem in the torque converter clutch solenoid valve B circuit.
P1773 Problem in A/T Clutch Pressure Control Solenoid Valve B Circuit: Repeated code, likely a typo in the source.
P1790 Throttle Position (TP) Sensor Circuit Malfunction: Repeated code, likely a typo in the source.
P1791 Vehicle Speed Sensor (VSS) Range/Performance Problem: Repeated code, likely a typo in the source.
P1792 Problem in Engine Coolant Temperature (ECT) Sensor Circuit: Repeated code, likely a typo in the source.
P1793 Manifold Absolute Pressure Sensor Circuit: Repeated code, likely a typo in the source.
P1870 Problem in CVT Speed Change Control Valve Assembly Circuit: Problem in the CVT speed change control valve assembly circuit.
P1873 Problem in CVT Pulley Pressure Control Valve Assembly Circuit: Problem in the CVT pulley pressure control valve assembly circuit.
P1879 Problem in CVT Start Clutch Pressure Control Valve Assembly Circuit: Problem in the CVT start clutch pressure control valve assembly circuit.
P1882 Problem in Inhibitor Solenoid Circuit: Problem in the inhibitor solenoid circuit (likely CVT related).
P1884 Secondary Gear Speed Sensor 2 Circuit Malfunction: Malfunction in the secondary gear speed sensor 2 circuit (likely CVT related).
P1885 CVT Drive Pulley Speed Sensor Circuit: Problem in the CVT drive pulley speed sensor circuit.
P1886 CVT Driven Pulley Speed Sensor Circuit: Problem in the CVT driven pulley speed sensor circuit.
P1888 CVT Speed Sensor: General CVT speed sensor issue.
P1889 Problem in CVT Speed Sensor 2 Circuit: Problem in the CVT speed sensor 2 circuit.
P1890 Shift Control System: Repeated code, likely a typo in the source.
P1891 Problem in Start Clutch System: Problem in the start clutch system (likely CVT related).
P1894 CVT Speed Change Control Valve Circuit: Problem in the CVT speed change control valve circuit.
P1895 CVT Pulley Pressure Control Valve Circuit: Problem in the CVT pulley pressure control valve circuit.

P2100-P2A99: Throttle Actuator and Fuel/Air Ratio

P2101 Throttle Actuator System Malfunction: General malfunction in the throttle actuator system.
P2108 Throttle Actuator Control Module Problem: Problem with the throttle actuator control module.
P2118 Throttle Actuator Current Range/Performance Problem: Throttle actuator current reading outside of expected range or performance issues.
P2122 Accelerator Pedal Position (APP) Sensor 1 (Throttle Position Sensor D) Circuit Low Voltage: Low voltage in the APP sensor 1 (TPS D) circuit.
P2123 Accelerator Pedal Position (APP) Sensor 1 (Throttle Position Sensor D) Circuit High Voltage: High voltage in the APP sensor 1 (TPS D) circuit.
P2127 Accelerator Pedal Position (APP) Sensor 2 (Throttle Position Sensor E) Circuit Low Voltage: Low voltage in the APP sensor 2 (TPS E) circuit.
P2128 Accelerator Pedal Position (APP) Sensor 2 (Throttle Position Sensor E) Circuit High Voltage: High voltage in the APP sensor 2 (TPS E) circuit.
P2135 Throttle Position (TP) Sensor 1/2 Incorrect Voltage Correlation: Incorrect voltage correlation between TP sensor 1 and 2.
P2138 Accelerator Pedal Position (APP) Sensor 1/2 (Throttle Position Sensor D/E) Incorrect Voltage Correlation: Incorrect voltage correlation between APP sensor 1 and 2 (TPS D/E).
P2176 Throttle Actuator Control System Idle Position Not Learned: Throttle actuator control system idle position not learned or calibrated.
P2195 Air/Fuel Ratio (A/F) Sensor (Sensor 1) Signal Stuck Lean: Air/Fuel Ratio sensor (sensor 1) signal is stuck indicating a lean condition.
P2197 Front Air/Fuel Ratio (A/F) Sensor (Bank 2, Sensor 1) Signal Stuck Lean: Front Air/Fuel Ratio sensor (Bank 2, sensor 1) signal stuck lean.
P2227 Barometric Pressure (BARO) Sensor Circuit Range/Performance Problem: Repeated code, likely a typo in the source.
P2228 Barometric Pressure (BARO) Sensor Circuit Low Voltage: Repeated code, likely a typo in the source.
P2229 Barometric Pressure (BARO) Sensor Circuit High Voltage: Repeated code, likely a typo in the source.
P2237 Rear Air/Fuel Ratio (A/F) Sensor (Bank 1, Sensor 1) IP Line High Voltage: High voltage on the IP line of the rear Air/Fuel Ratio sensor (Bank 1, sensor 1).
P2238 Air/Fuel Ratio (A/F) Sensor (Sensor 1) AFS+ Line Low Voltage: Repeated code, likely a typo in the source.
P2238 Rear Air/Fuel Ratio (A/F) Sensor (Bank 1, Sensor 1) IP Line Low Voltage: Low voltage on the IP line of the rear Air/Fuel Ratio sensor (Bank 1, sensor 1).
P2240 Front Air/Fuel Ratio (A/F) Sensor (Bank 2, Sensor 1) IP Line High Voltage: High voltage on the IP line of the front Air/Fuel Ratio sensor (Bank 2, sensor 1).
P2241 Front Air/Fuel Ratio (A/F) Sensor (Bank 2, Sensor 1) IP Line Low Voltage: Low voltage on the IP line of the front Air/Fuel Ratio sensor (Bank 2, sensor 1).
P2243 Rear Air/Fuel Ratio (A/F) Sensor (Bank 1, Sensor 1) VCENT Line High Voltage: High voltage on the VCENT line of the rear Air/Fuel Ratio sensor (Bank 1, sensor 1).
P2245 Rear Air/Fuel Ratio (A/F) Sensor (Bank 1, Sensor 1) VCENT Line Low Voltage: Low voltage on the VCENT line of the rear Air/Fuel Ratio sensor (Bank 1, sensor 1).
P2247 Front Air/Fuel Ratio (A/F) Sensor (Bank 2, Sensor 1) VCENT Line High Voltage: High voltage on the VCENT line of the front Air/Fuel Ratio sensor (Bank 2, sensor 1).
P2249 Front Air/Fuel Ratio (A/F) Sensor (Bank 2, Sensor 1) VCENT Line Low Voltage: Low voltage on the VCENT line of the front Air/Fuel Ratio sensor (Bank 2, sensor 1).
P2251 Rear Air/Fuel Ratio (A/F) Sensor (Bank 1, Sensor 1) VS Line High Voltage: High voltage on the VS line of the rear Air/Fuel Ratio sensor (Bank 1, sensor 1).
P2252 Air/Fuel Ratio (A/F) Sensor (Sensor 1) AFS- Line Low Voltage: Repeated code, likely a typo in the source.
P2254 Front Air/Fuel Ratio (A/F) Sensor (Bank 2, Sensor 1) VS Line High Voltage: High voltage on the VS line of the front Air/Fuel Ratio sensor (Bank 2, sensor 1).
P2255 Front Air/Fuel Ratio (A/F) Sensor (Bank 2, Sensor 1) VS Line Low Voltage: Low voltage on the VS line of the front Air/Fuel Ratio sensor (Bank 2, sensor 1).
P2279 Intake Air System Leak: Leak detected in the intake air system.
P2413 Exhaust Gas Recirculation (EGR) System Range/Performance Problem: Repeated code, likely a typo in the source.
P2422 Evaporative Emission (EVAP) System Vent Shut Valve Close Malfunction: Malfunction in the EVAP system vent shut valve being closed.
P2552 Throttle Actuator Control Module Relay Malfunction: Malfunction in the throttle actuator control module relay.
P2627 Rear Air/Fuel Ratio (A/F) Sensor (Bank 1, Sensor 1) LABEL Circuit Low Voltage: Low voltage on the LABEL circuit of the rear Air/Fuel Ratio sensor (Bank 1, sensor 1).
P2628 Rear Air/Fuel Ratio (A/F) Sensor (Bank 1, Sensor 1) LABEL Circuit High Voltage: High voltage on the LABEL circuit of the rear Air/Fuel Ratio sensor (Bank 1, sensor 1).
P2630 Front Air/Fuel Ratio (A/F) Sensor (Bank 2, Sensor 1) LABEL Circuit Low Voltage: Low voltage on the LABEL circuit of the front Air/Fuel Ratio sensor (Bank 2, sensor 1).
P2631 Front Air/Fuel Ratio (A/F) Sensor (Bank 2, Sensor 1) LABEL Circuit High Voltage: High voltage on the LABEL circuit of the front Air/Fuel Ratio sensor (Bank 2, sensor 1).
P2646 VTEC Oil Pressure Switch Circuit Low Voltage: Low voltage in the VTEC oil pressure switch circuit.
P2647 VTEC Oil Pressure Switch Circuit High Voltage: High voltage in the VTEC oil pressure switch circuit.
P2648 VTEC Solenoid Valve Circuit Low Voltage: Low voltage in the VTEC solenoid valve circuit.
P2649 VTEC Solenoid Valve Circuit High Voltage: High voltage in the VTEC solenoid valve circuit.
P2769 Short in Torque Converter Clutch Solenoid Valve Circuit: Short circuit in the torque converter clutch solenoid valve circuit.
P2770 Open in Torque Converter Clutch Solenoid Valve Circuit: Open circuit in the torque converter clutch solenoid valve circuit.
P2A00 Air/Fuel Ratio (A/F) Sensor (Sensor 1) Range/Performance Problem: Repeated code, likely a typo in the source.
P2A03 Front A/F Sensor Circuit (Bank 2, Sensor 1) Circuit Range/Performance Problem: Front Air/Fuel Ratio sensor (Bank 2, sensor 1) circuit reading outside of expected range or performance issues.

U0001-U0999: Network Communication

U0073 FCAN Malfunction (Bus-off): Fault CAN (Controller Area Network) communication bus, bus-off condition.
U0107 Lost Communication With Throttle Actuator Control Module: Loss of communication with the Throttle Actuator Control Module.
U0121 FCAN Malfunction (TCS-PCM): Fault CAN communication between TCS (Traction Control System) and PCM.
U0155 FCAN Malfunction (Gauge Control Module-ECM/PCM): Fault CAN communication between the Gauge Control Module and ECM/PCM.

Note: This list is based on Honda Service Bulletin #03-020 and provides a comprehensive overview of potential OBD2 codes for Honda Civic models. For accurate diagnosis and repair, always consult a qualified automotive technician and refer to the specific service manual for your Honda Civic model year. Using an OBD2 scanner is crucial for retrieving these codes, and understanding their descriptions is the first step towards resolving any issues indicated by your check engine light.