Decoding Your Integra OBD2 Check Engine Codes: A Comprehensive Guide

Encountering a check engine light in your Honda Integra can be concerning. Modern vehicles like the Integra utilize an On-Board Diagnostics system, specifically OBD2, to monitor various components and systems. When an issue arises, the system illuminates the check engine light and stores diagnostic trouble codes (DTCs). These “Integra Obd2 Check Engine Codes” are crucial for pinpointing problems and facilitating effective repairs. This guide provides a comprehensive list of OBD codes relevant to your Integra, helping you understand what these codes mean and how to proceed with diagnosing the issue.

Understanding OBD2 and Check Engine Lights

The OBD2 system is standardized across most vehicles manufactured after 1996, including the Honda Integra. It’s designed to help both vehicle owners and technicians identify malfunctions quickly. When your Integra’s check engine light comes on, it signifies that the car’s computer has detected a problem that could affect emissions, performance, or both. These problems range from minor issues like a loose gas cap to more serious concerns such as catalytic converter failure. The OBD2 system stores a code that corresponds to the detected problem, which can be retrieved using an OBD2 scanner.

Common Integra OBD2 Check Engine Codes

Below is a detailed list of OBD codes that may trigger the check engine light in your Honda Integra. While this list is comprehensive, it’s important to remember that specific codes and their implications can vary slightly depending on the Integra model year and engine type. Always consult your Integra’s repair manual for the most accurate information.

OBD 0/1/2 CEL Codes: (These codes are generally applicable to Honda/Acura vehicles and likely to be relevant for Integra models compatible with OBD2)

• 0 – ECU – Faulty ECU or ECU ROM: This code indicates a problem with the Engine Control Unit (ECU) itself, which is the car’s computer. It might be a hardware failure or a software issue within the ECU. Diagnostic Proceedure (This link is from the original text, keep it for reference if contextually relevant on the target website)
• 1 – O2A – Oxygen sensor #1: Refers to the primary oxygen sensor, usually located before the catalytic converter. This sensor measures the oxygen content in the exhaust gas to help the ECU adjust the fuel mixture.
• 2 – O2B – Oxygen sensor #2: Indicates an issue with the secondary oxygen sensor, positioned after the catalytic converter. This sensor monitors the catalytic converter’s efficiency.
• 3 – MAP – Manifold Absolute Pressure Sensor: The MAP sensor measures the pressure inside the intake manifold. Faulty readings can affect fuel delivery and engine performance.
• 4 – CKP – Crank Position Sensor: The Crank Position Sensor monitors the position and rotational speed of the crankshaft. It’s crucial for ignition timing and fuel injection.
• 5 – MAP – Manifold Absolute Pressure Sensor: (Duplicate code, likely a typo in the original list, should be verified against official Honda documentation if possible for ultimate accuracy, but for now, keep it as is to reflect the original list).
• 6 – ECT – Engine Coolant Temperature Sensor: This sensor measures the engine coolant temperature. Incorrect readings can lead to poor engine performance and overheating issues.
• 7 – TPS – Throttle Position Sensor: The TPS monitors the throttle valve’s position, informing the ECU about driver input and load demand.
• 8 – TDC – Top Dead Center Sensor: This sensor, often integrated with the distributor or crankshaft sensor, helps determine the top dead center position of the pistons for ignition and injection timing.
• 9 – CYP – Cylinder Sensor: The Cylinder Position Sensor identifies which cylinder is firing, important for sequential fuel injection.
• 10 – IAT – Intake Air Temperature Sensor: The IAT sensor measures the temperature of the air entering the intake manifold. This data is used to adjust fuel mixture and timing based on air density. Diagnostic Proceedure (Keep link)
• 11 – Engine Overheating: This code directly indicates that the engine has overheated. It could be due to various issues in the cooling system.
• 12 – EGR – Exhaust Gas Recirculation Lift Valve: The EGR system reduces NOx emissions by recirculating a portion of the exhaust gas back into the intake manifold. This code points to a problem with the EGR valve or system.
• 13 – BARO – Atmospheric Pressure Sensor: The Barometric Pressure sensor measures the ambient air pressure. It helps the ECU adjust for altitude changes.
• 14 – IAC (EACV) – Idle Air Control Valve: The IAC valve controls the engine’s idle speed. A malfunction can cause idle issues. (EACV – Electronic Air Control Valve, another name for IAC in some Honda systems).
• 15 – Ignition Output Signal: This code indicates a problem with the signal from the ECU to the ignition system.
• 16 – Fuel Injectors: Points to a malfunction in the fuel injector circuit or the injectors themselves.
• 17 – VSS – Vehicle Speed Sensor: The VSS measures the vehicle’s speed and is used by various systems, including the speedometer and transmission control.
• 19 – Automatic Transmission Lockup Control Valve: For automatic transmission Integras, this code relates to the torque converter lockup function, which improves fuel efficiency at higher speeds.
• 20 – ELD – Electrical Load Detector: The ELD monitors the electrical load on the charging system and helps optimize alternator output.
• 21 – VTEC Spool Solenoid Valve: For Integra models with VTEC (Variable Valve Timing and Lift Electronic Control), this code relates to the VTEC solenoid valve that controls the engagement of the high-performance valve timing profile.
• 22 – VTEC Pressure Valve: Another VTEC related code, this one points to an issue with the oil pressure switch in the VTEC system.
• 23 – Knock Sensor: The knock sensor detects engine knocking or detonation, which can damage the engine.
• 30 – Automatic Transmission A Signal: A generic transmission-related code. Further diagnosis is needed to pinpoint the specific issue within the automatic transmission system.
• 31 – Automatic Transmission B Signal: Similar to code 30, indicates a general problem within the automatic transmission.
• 36 – Traction Control (found on some JDM ECU’s): This code might appear in Japanese Domestic Market (JDM) Integras that are equipped with traction control systems, which were not standard in all markets.
• 38 – Secondary VTEC Solenoid on JDM 3 stage D15B Vtec ECUs (P2J): Specifically for certain JDM Honda engines (like the D15B VTEC) with a 3-stage VTEC system, indicating a problem with the secondary VTEC solenoid. (P2J is a specific ECU code).
• 41 – Primary Oxygen Sensor Heater: Indicates a problem with the heater circuit of the primary oxygen sensor. The heater is used to bring the sensor to operating temperature quickly for accurate readings.
• 43 – Fuel Supply System: A general code suggesting an issue within the fuel delivery system. Could be fuel pump, fuel filter, fuel pressure regulator, or related components.
• 45 – Fuel System Too Rich or Lean: Indicates that the air-fuel mixture is either too rich (too much fuel) or too lean (too little fuel). This can be caused by various sensor or component failures.
• 48 – LAF – Lean Air Fuel Sensor: Some newer Honda/Acura vehicles use a Lean Air Fuel (LAF) sensor instead of a traditional oxygen sensor. This code indicates a problem with the LAF sensor circuit.
• 54 – CKF – Crank Fluctuation Sensor: A more advanced crankshaft sensor that detects fluctuations in crankshaft speed, often used for misfire detection and more precise engine control.
• 58 – TDC Sensor #2: Some Honda engines may use a secondary TDC sensor. This code indicates a problem with that sensor.
• 61 – Primary Oxygen Sensor: (Duplicate of code 1, possibly listed again for clarity or different context in some documentation – keep as is to reflect original list).
• 63 – Secondary Oxygen Sensor Circuit: (Similar to code 2 but might be more specific to the sensor circuit – keep as is).
• 65 – Secondary Oxygen Sensor Heater Wire (black wires): Specifically points to the heater circuit wiring (often black wires) of the secondary oxygen sensor.
• 67 – Catalytic Converter Efficiency Below Threshold: Indicates that the catalytic converter is not functioning efficiently enough to reduce emissions.
• 71 – Random Misfire Cylinder 1: A misfire occurs when combustion is incomplete or absent in a cylinder. This code indicates a random misfire specifically in cylinder 1.
• 72 – Random Misfire Cylinder 2: Random misfire in cylinder 2.
• 73 – Random Misfire Cylinder 3: Random misfire in cylinder 3.
• 74 – Random Misfire Cylinder 4: Random misfire in cylinder 4. (Integra engines are typically 4-cylinder, so these misfire codes are directly relevant).
• 80 – EGR Valve/Line: (Similar to code 12, but possibly more general, including issues with EGR lines – keep as is).
• 86 – ECT Sensor – Cooling System: (Similar to code 6, but specifically mentioning the cooling system context – keep as is).
• 91 – Fuel Tank Pressure Sensor: Part of the EVAP (Evaporative Emission Control System), this sensor monitors pressure in the fuel tank.
• 92 – EVAP Solenoid/Valve/Vacuum Lines: Indicates a problem within the EVAP system, possibly with the EVAP solenoid, valve, or vacuum lines.

OBD1 TCU Codes: (These are specifically Transmission Control Unit codes and may be less directly related to the “check engine light” in some OBD2 systems, but are listed in the original source, so include for completeness, noting they are TCU specific).

• 1 – Lock-up solenoid ‘A’ circuit open or shorted: Relates to the automatic transmission torque converter lockup solenoid A.
• 2 – Lock-up solenoid ‘B’ circuit open or shorted: Relates to the automatic transmission torque converter lockup solenoid B.
• 3 – Throttle Position Sensor circuit open or shorted: (While TPS is listed in CEL codes, it can also affect TCU operation and trigger TCU codes).
• 4 – Vehicle Speed Sensor open or shorted – No signal from speedometer: (VSS is crucial for both engine and transmission control).
• 5 – Shift Lever Position Switch circuit shorted: Indicates a problem with the switch that detects the position of the gear shift lever.
• 6 – Shift Lever Position Switch circuit open: Another issue with the gear shift lever position switch.
• 7 – Shift Solenoid ‘A’ circuit open or shorted: Relates to shift solenoid A in the automatic transmission.
• 8 – Shift Solenoid ‘B’ circuit open or shorted: Relates to shift solenoid B in the automatic transmission.
• 9 – Counter shaft or transmission speed pulse generator open or shorted: Indicates a problem with the transmission speed sensor (counter shaft speed).
• 10 – Coolant Temperature Sensor open or shorted: (ECT sensor can also affect TCU operation).
• 11 – Engine RPM (Ignition coil signal) open or shorted: (Engine RPM signal is important for transmission control).
• 12 – (No code 12 used): As noted, code 12 is not used in this TCU code set.
• 13 – Main shaft speed pulse generator open or shorted: Another transmission speed sensor issue (main shaft speed).
• 14 – Linear (line pressure control) solenoid open or shorted: Relates to the linear solenoid that controls transmission line pressure.
• 15 – Kick down switch circuit shorted: The kick-down switch is used for forced downshifts in automatic transmissions.

Using Integra OBD2 Check Engine Codes for Diagnosis

When your Integra’s check engine light illuminates, the first step is to retrieve the stored OBD2 code using a scanner. These scanners are readily available and relatively inexpensive. Once you have the code, consult this list or a dedicated Integra repair resource to understand the potential issue.

It’s important to note that an OBD2 code provides a starting point for diagnosis, not a definitive solution. Further investigation is usually required to pinpoint the exact cause of the problem. For example, a code indicating an oxygen sensor issue could be due to a faulty sensor, wiring problems, exhaust leaks, or even issues upstream affecting the sensor reading.

Conclusion

Understanding your Integra OBD2 check engine codes is the first step towards resolving car trouble and maintaining your vehicle’s health. This guide provides a comprehensive list to help you decipher those codes. Remember to use this information as a starting point for diagnosis and always consult a qualified mechanic if you are unsure about how to proceed with repairs. By being proactive and informed about your Integra’s OBD2 system, you can ensure its longevity and performance.