Understanding your Honda’s On-Board Diagnostics II (OBD2) system is crucial for modern vehicle maintenance and troubleshooting. The OBD2 port provides access to your car’s computer, allowing mechanics and car enthusiasts to read diagnostic trouble codes, monitor vehicle parameters, and ensure optimal performance. This article will delve into the specifics of the Honda Obd2 Pinout, offering a detailed guide to each pin and its function, along with essential compatibility information and diagnostic code examples.
Decoding the Honda OBD2 Pinout
The OBD2 connector is a standardized 16-pin interface found in most modern vehicles, including Hondas manufactured from the mid-1990s onwards. However, understanding the function of each pin is essential for accurate diagnostics and communication with your vehicle’s systems. Below is a detailed breakdown of the Honda OBD2 pinout, outlining the signal and description for each relevant pin:
| Pin | Signal | Description |
|---|---|---|
| 4 | CGND | Chassis Ground |
| 5 | SGND | Signal Ground |
| 6 | CAN High | CAN Bus High (J-2284) |
| 7 | K-LINE | K-Line for ISO 9141-2 and ISO/DIS 14230-4 protocols |
| 9 | SCS | Service Check System – Used for retrieving specific Honda diagnostic codes |
| 12 | Programming Output (often unused) | |
| 14 | CAN Low | CAN Bus Low (J-2284) |
| 15 | ISO 9141-2 L-LINE | L-Line for ISO 9141-2 and ISO/DIS 14230-4 protocols |
| 16 | +12V | Battery Power (Unswitched) |
It’s important to note that not all pins are universally used across all Honda models or OBD2 protocols. Some pins are protocol-specific or may be reserved for manufacturer-specific functions. For Honda, understanding pins 4, 5, 6, 7, 9, 14, 15, and 16 is particularly relevant for diagnostics.
- Pin 4 & 5 (Grounds): These pins provide the necessary ground connections for the OBD2 interface to function correctly. Pin 4 is Chassis Ground, grounded to the vehicle’s chassis, while Pin 5 is Signal Ground, serving as a reference ground for the communication signals.
- Pin 6 & 14 (CAN Bus): These pins are part of the Controller Area Network (CAN) bus, a high-speed communication protocol prevalent in modern vehicles. CAN High (Pin 6) and CAN Low (Pin 14) enable communication for systems adhering to the J-2284 standard, commonly used in newer Honda models.
- Pin 7 & 15 (K-Line and L-Line): These pins are used for communication based on the ISO 9141-2 and ISO 14230-4 (KWP2000) protocols. K-Line (Pin 7) is a bidirectional communication line, while L-Line (Pin 15) was traditionally used for wake-up signals in some systems. These protocols are often found in older OBD2 compliant Hondas.
- Pin 9 (SCS): The Service Check System (SCS) pin is unique to Honda and some other manufacturers. Bridging this pin to ground can trigger the retrieval of specific diagnostic codes, often displayed through blinking lights on the dashboard, without the need for an OBD2 scanner.
- Pin 16 (Battery Power): This pin provides a direct, unswitched +12V power supply from the vehicle’s battery to the OBD2 diagnostic tool, ensuring it has power to operate when connected.
Understanding these pin functions is essential when using OBD2 scanners, interfaces, or when building custom diagnostic tools for Honda vehicles.
Honda OBD2 Compatibility Across Models
While OBD2 became a standard in 1996 in the United States and later in other regions, the specific protocols and implementation can vary across different Honda models and production years. The following table provides a general compatibility overview, but it’s important to remember that this list is not exhaustive and specifications can vary. Always consult your vehicle’s documentation for the most accurate information.
| Model | Engine | Year (starting from) | OBD-2 Protocol |
|---|---|---|---|
| Honda Accord | 1998 | ISO 14230-4, ISO 9141-2 | |
| 2.0 iES, Gasoline (147HP) | 1998 | ISO 9141 | |
| 2000 | ISO 14230-4, ISO 9141-2 | ||
| 2.2 CTDI, Diesel (139 HP) | 2005 | ISO 9141-2 | |
| Gasoline (188 HP) | 2006 | ||
| Honda Accord Coupe | Gasoline (198 HP) | 2001 | ISO 9141-2 |
| Honda CITY TYPE Z | Gasoline (155 HP) | 1999 | – |
| Honda Civic | 1996 | ISO 14230-4, ISO 9141-2 | |
| 2000 | ISO 14230-4, ISO 9141-2 | ||
| 1.4 IS, Gasoline (90HP) | 2000 | ISO 9141 | |
| 2001 | ISO 14230-4, ISO 9141-2 | ||
| Diesel (100 HP) | 2003 | ISO 14230-4, ISO 9141-2 | |
| 1.7 mfi, Gasoline (115HP) | 2003 | ISO 9141 | |
| 2, Gasoline (200HP) | 2003 | ISO 9141 | |
| 1.7 CTDI, Diesel (100HP) | 2004 | ISO 9141 | |
| 2.0 16V, Gasoline (200HP) | 2005 | ISO 9141 | |
| Gasoline (112 HP) | 2006 | ||
| 1.4 I-DSI, Gasoline (83HP) | 2006 | CAN 29bit | |
| 1.8, Gasoline (140HP) | 2006 | CAN 29bit | |
| 2.2 i-CtdI, Diesel (140HP) | 2006 | CAN 29bit | |
| 1.8, Gasoline (140HP) | 2009 | CAN 29bit | |
| Honda civic coupe em2 | Gasoline (120 HP) | 2001 | ISO 9141-2 |
| Honda Civic Del Sol | 1997 | ISO 14230-4, ISO 9141-2 | |
| Honda Civic EV1 | Gasoline (159 HP) | 2005 | ISO 9141-2 |
| Honda Civic Type R | 2003 | ISO 14230-4, ISO 9141-2 | |
| Honda Civic TypeR-FN2 | Gasoline (199 HP) | 2007 | ISO 9141-2 |
| Honda CR-V | Diesel (139 HP) | 2006 | |
| 2.2 CDTI, Diesel (140HP) | 2005 | ISO 9141 | |
| Gasoline (148 HP) | 2002 | ISO 9141-2 | |
| Diesel (148 HP) | 2010 | ISO 9141-2 | |
| Honda CR-Z | 1.5, Hyb (124HP) | 2010 | CAN 29bit |
| Honda Fit | 1.2, Gasoline (65HP) | 2003 | ISO 9141 |
| Honda FR-V | 2.2 CDTI, Diesel (140HP) | 2006 | ISO 9141 |
| Honda HR-V | 1.6, Gasoline (124HP) | 2001 | ISO 9141 |
| Honda Jazz | 1.2, Gasoline (80HP) | 2002 | ISO 9141 |
| 1.4, Gasoline (82 HP) | 2003 | ||
| 1.2, Gasoline (65HP) | 2003 | ISO 9141 | |
| 1.2, Gasoline (104 HP) | 2004 | ||
| 1.4 i-dsi cvt, Gasoline (83HP) | 2005 | ISO 9141 | |
| Honda Legend | Gasoline (171 HP) | 1990 | – |
| 3.5 VTEC, Gasoline (295HP) | 2006 | ISO 9141 | |
| Honda Odyssey | 2002 | ISO 14230-4, ISO 9141-2 | |
| Honda rd8 | Gasoline (149 HP) | 2002 | – |
| Honda S2000 | 2.0 dohc 16s, Gasoline (240HP) | 2002 | ISO 9141 |
| 2000 | ISO 14230-4, ISO 9141-2 | ||
| Gasoline (238 HP) | 2006 | ||
| Honda Stream 2.0 | Gasoline (155 HP) | 2004 | |
| Honda TYPE R | Gasoline (249 HP) | 2005 |
Key OBD Interface Timeline for Honda:
- 1996 – 2006: Predominantly ISO 9141 protocol.
- 2006 – 2008: Transition period with vehicles potentially using ISO 9141 or CAN.
- 2008 and later: Primarily CAN (Controller Area Network) protocol.
This timeline serves as a general guideline, and it’s always recommended to verify your specific Honda model’s OBD2 protocol for accurate diagnostics.
Understanding Honda Specific Diagnostic Trouble Codes (DTCs)
OBD2 systems use standardized diagnostic trouble codes (DTCs) to indicate various vehicle issues. While generic OBD2 codes are common across manufacturers, Honda also utilizes specific codes for more detailed diagnostics. Here are some examples of Honda specific DTCs:
| Code | Description |
|---|---|
| P1106 | Barometric Pressure Circuit Range/Performance |
| P1107 | Barometric Pressure Circuit Low Input |
| P1108 | Barometric Pressure Circuit High Input |
| P1121 | Throttle Position Lower Than Expected |
| P1122 | Throttle Position Higher Than Expected |
| P1128 | MAP Lower Than Expected |
| P1129 | MAP Higher Than Expected |
| P1149 | Primary HO2S (Sensor 1) Circuit Range/Performance Problem |
| P1162 | Primary HO2S (No. 1) Circuit Malfunction |
| P1163 | Primary HO2S (No. 1) Circuit Slow Response |
| P1164 | Primary HO2S (No. 1) Circuit Range/Performance |
| P1165 | Primary HO2S (No. 1) Circuit Range/Performance |
| P1166 | Primary HO2S (No. 1) Heater System Electrical |
| P1167 | Primary HO2S (No. 1) Heater System |
| P1168 | Primary HO2S (No. 1) LABEL Low Input |
| P1169 | Primary HO2S (No. 1) LABEL High Input |
| P1253 | VTEC System Malfunction |
| P1257 | VTEC System Malfunction |
| P1258 | VTEC System Malfunction |
| P1259 | VTEC System Malfunction |
| P1297 | Electrical Load Detector Circuit Low Input |
| P1298 | Electrical Load Detector Circuit High Input |
| P1300 | Multiple Cylinder Misfire Detected |
| P1336 | CSF Sensor Intermittent Interruption |
| P1337 | CSF Sensor No Signal |
| P1359 | CKP/TDC Sensor Connector Disconnection |
| P1361 | Intermittent Interruption In TDC 1 Sensor Circuit |
| P1362 | No Signal In TDC 1 Sensor Circuit |
| P1366 | Intermittent Interruption In TDC 2 Sensor Circuit |
| P1367 | No Signal In TDC 2 Sensor Circuit |
| P1381 | Cylinder Position Sensor Intermittent Interruption |
| P1382 | Cylinder Position Sensor No Signal |
| P1456 | EVAP Emission Control System Leak Detected (Fuel Tank System) |
| P1457 | EVAP Emission Control System Leak Detected (Control Canister System) |
| P1459 | EVAP Emission Purge Flow Switch Malfunction |
| P1486 | Thermostat Range/Performance Problem |
| P1491 | EGR Valve Lift Insufficient Detected |
| P1498 | EGR Valve Lift Sensor High Voltage |
| P1508 | IAC Valve Circuit Failure |
| P1509 | IAC Valve Circuit Failure |
| P1519 | Idle Air Control Valve Circuit Failure |
| P1607 | ECM/PCM Internal Circuit Failure A |
| P1655 | SEAF/SEFA/TMA/TMB Signal Line Failure |
| P1656 | Automatic Transaxle |
| P1660 | Automatic Transaxle FI Signal A Circuit Failure |
| P1676 | FPTDR Signal Line Failure |
| P1678 | FPTDR Signal Line Failure |
| P1681 | Automatic Transaxle FI Signal A Low Input |
| P1682 | Automatic Transaxle FI Signal A High Input |
| P1686 | Automatic Transaxle FI Signal B Low Input |
| P1687 | Automatic Transaxle FI Signal B High Input |
| P1705 | Automatic Transaxle Concerns |
| P1706 | Automatic Transaxle Concerns |
| P1738 | Automatic Transaxle Concerns |
| P1739 | Automatic Transaxle Concerns |
| P1753 | Automatic Transaxle Concerns |
| P1758 | Automatic Transaxle Concerns |
| P1768 | Automatic Transaxle Concerns |
| P1773 | Automatic Transaxle Concerns |
| P1785 | Automatic Transaxle Concerns |
| P1786 | Automatic Transaxle Concerns |
| P1790 | Automatic Transaxle Concerns |
| P1791 | Automatic Transaxle Concerns |
| P1792 | Automatic Transaxle Concerns |
| P1793 | Automatic Transaxle Concerns |
| P1794 | Automatic Transaxle Concerns |
| P1870 | Automatic Transaxle Concerns |
| P1873 | Automatic Transaxle Concerns |
| P1879 | Automatic Transaxle Concerns |
| P1885 | Automatic Transaxle Concerns |
| P1886 | Automatic Transaxle Concerns |
| P1888 | Automatic Transaxle Concerns |
| P1890 | Automatic Transaxle Concerns |
| P1891 | Automatic Transaxle Concerns |
These codes are invaluable for diagnosing issues related to various systems, from engine performance (VTEC, misfires) to emissions (EVAP, EGR) and transmission problems. When using an OBD2 scanner, understanding whether a code is generic or manufacturer-specific can aid in accurate troubleshooting.
Essential OBD-II Cable Schematics
For advanced diagnostics or custom OBD2 setups, understanding cable schematics is vital. Here are some useful links to OBD-II cable schemes that are relevant to Honda vehicles and various OBD2 protocols:
- OBD-2 ISO 9141-2 (14230-4, KWP2000) simple serial cable
- OBD-2 J1850 PWM, J1850 VPW serial ELM327 cable
- OBD-2 universal ISO 15765-4 CAN, SAE J1850 PWM, SAE J1850 VPW, ISO 9141-2, ISO 14230-4 and SAE J1939 diagnostic cable
These resources provide detailed pinout diagrams for creating or understanding different types of OBD2 cables, catering to various communication protocols and diagnostic needs.
Conclusion
Having a solid understanding of the Honda OBD2 pinout, compatibility, and diagnostic codes is a powerful asset for anyone involved in Honda vehicle maintenance and repair. Whether you are a professional mechanic or a dedicated car owner, this knowledge empowers you to effectively diagnose issues, utilize diagnostic tools correctly, and keep your Honda running smoothly. By leveraging the information provided in this guide, you can confidently navigate the complexities of your Honda’s OBD2 system.
