Wiring
OBD1 ECU Code Compatibility Guide
Guide to OBD1 ECU code compatibility, detailing VTEC requirements, sensor exclusions (O2/Knock), and regional (USDM/JDM/...
VTEC Solenoid
The VTEC spool valve solenoid activates high-cam lobe profiles. How the ECU triggers VTEC, pressure switches, and troubl...
Automatic to Manual ECU Conversion
Overview of converting automatic Honda ECUs for manual transmission use through software or hardware modifications.
Atmospheric Pressure
An overview of atmospheric pressure and its significance in engine management, with reference unit conversions.
Honda OBD Generations Guide (OBD0 to OBD2)
An overview of Honda OBD0, OBD1, and OBD2 diagnostic systems, highlighting key differences, connector layouts, and code...
Vehicle Speed Sensor (VSS)
The Vehicle Speed Sensor (VSS) sends speed pulses to the cluster and ECU. Diagnosing speedo failures and VSS-related VTE...
Honda OBD1 ECU Reference (1992–1995)
Technical overview of OBD1 (1992–1995) Honda Engine Control Units, including popular ECU models and their applications.
Combustion Chamber
An overview of the engine combustion chamber, its role in the ignition process, and its influence on engine performance.
Honda Data Link Connector (DLC) Reference
Technical reference and location guide for the Honda 3-pin (OBD0/OBD1) and standardized 16-pin (OBD2) Data Link Connecto...
Index of Honda ECU Connections & Pinouts
Index of Honda and Acura ECU connector pinouts, wiring diagrams, and harness conversion guides across OBD0, OBD1, and OB...
Mass Air Flow (MAF) Sensor
Technical explanation of Mass Air Flow (MAF) sensors, detailing their function and highlighting differences compared to...
OBD1 ECU J12 Jumper Reference
Technical explanation of J12 jumper functionality on OBD1 Honda ECUs for datalogging and serial communication.
Spark Plug Technical Reference
An overview of the spark plug function within the combustion cycle and its role in ignition systems.
OBD2 Diagnostics Standard
Overview of the OBD2 standardized diagnostic protocol (1996+), including its standardized DLC port and diagnostic report...
Peak and Hold (Low Impedance) Injectors
Technical overview of Peak and Hold (low impedance) fuel injectors, their operation, and the requirement for resistor bo...
A/C Thermostat Switch Bypass
Guide for jumping the A/C thermostat switch during A/C system troubleshooting or installation.
Automatic Accord OBD2-to-OBD1 Conversion Guide
Wiring conversion guide and pinout translation tables for running an automatic OBD2a Honda Accord using an automatic OBD...
MCU Readers and ROM Dumping
Technical overview of MCU reading methods, exploiting hardware design vulnerabilities in early Oki microcontrollers for...
OBD1 CN2 Serial Port Reference
Technical reference for the OBD1 ECU CN2 serial port, detailing its pinout and role in datalogging.
OBD1 Oki 66207 Reader (DIP64)
Technical guide for dumping the internal ROM contents of a DIP64 Oki 66207 microcontroller using a custom reader interfa...
P08 OBD1 ECU Reference
Overview of the P08 OBD1 ECU, used in VTi/VXi (D15B SOHC VTEC) models, featuring a 1-wire O2 sensor setup.
Wideband O2 Sensor Installation Guide
Installation and configuration guide for AEM wideband O2 sensors on OBD1 Honda ECUs.
ECU Conversion Guide: 02D01980-1500 Board
Hardware modification guide for converting the 02D01980-1500 Honda ECU board, including components required for VTEC and...
Acura Integra PR4 OBD0 ECU Pinouts
Pinout information and wiring reference for the OBD0 Acura Integra PR4 ECU (B18A1 engine).
Analog-to-Digital Conversion (ADC)
An overview of Analog-to-Digital Conversion (ADC) in automotive ECU applications, including resolution and reference vol...
Check Engine Light (CEL)
An explanation of the Check Engine Light (CEL), its function, and how to retrieve diagnostic trouble codes.
D16Z6 Swap Guide: OBD0 Chassis
Swap guide for installing a D16Z6 engine into an OBD0 (1988–1991) Civic or CRX, covering engine mounts, pulleys, and nec...
Desoldering Braid
An overview of desoldering braid (wick) and its use in removing solder from circuit boards.
Honda OBD0 to OBD1 Wiring Conversion Guide
Complete guide for converting 1988-1991 (OBD0) Honda wiring harnesses to run 1992-1995 (OBD1) ECUs, including engine har...
Non-VTEC to VTEC ECU Conversion
Guide for converting non-VTEC Honda ECUs to support VTEC operation, outlining necessary hardware modifications.
OBD0 Automatic ECU to Manual Conversion
Hardware modification guide for bypassing the automatic transmission lockup solenoid check (DTC 19) when running an auto...
OBD0 Oki 83C154 ROM Dumping Guide
Technical guide for dumping the internal ROM contents of an Oki 83C154 microcontroller, used in certain OBD0 ECUs.
OBD1 ECU Chipping Wirelist
Technical wirelist for OBD1 Honda ECU chipping, detailing connections for 74HC373 latch and ROM sockets.
OBD1 ECU ROM Conversion Formulas
Index of scaling formulas for converting raw hex values in OBD1 ECU ROM maps into readable engineering units.
OBD1 Oki 66207 Reader (PLCC68)
Technical guide for dumping the internal ROM contents of a PLCC68 Oki 66207 microcontroller using a custom reader interf...
Oxygen (O2) Sensor Heater Circuit
Overview of the Oxygen (O2) Sensor heater circuit, its function in maintaining sensor accuracy, and integration with Hon...
P05 OBD1 ECU Reference
Overview of the Honda P05 OBD1 ECU, originally found in 1992–1995 Civic CX (D15B8) models.
P14 to P13 ECU Conversion Guide
Technical guide for converting an OBD1 P14 (non-VTEC H23A1) ECU board to a VTEC-capable P13 (H22A) ECU.
EDM
Reference for EDM (European Domestic Market) Honda ECUs, detailing common hardware differences such as the lack of an in...
VTEC Conversion Guide: "1720" ECU Boards
Technical guide for converting non-VTEC "1720" Honda ECU boards to support VTEC operation, including component lists and...
5050s VTEC Conversion Fix
Troubleshooting and installation guide for using 5050s components in Honda VTEC conversion circuits to resolve MIL code...
Adding a Knock Sensor to a Honda ECU
Hardware modification guide for adding a knock sensor to a Honda P75/P72 ECU board.
Atmel AT29C010 Flash ROM
Technical overview of the Atmel AT29C010 1Mbit (128kb) FLASH-ROM chip, including its application in ECU tuning and pinou...
BAR (Unit of Pressure)
An overview of the BAR unit of pressure measurement and its relationship to atmospheric pressure and PSI.
DIY Datalogging Cable (Nokia FBUS Modification)
Technical guide to converting a legacy Nokia FBUS serial phone cable into a low-cost USB-to-TTL serial adapter for OBD1...
ECU Conversion Overview
An overview of ECU conversion procedures, allowing different OBD generations to be utilized through harness modification...
Engine Wiring Harness Reference
An overview of Honda engine wiring harnesses, detailing their role in ECU communication and connector differences across...
How ECU Datalogging Works
Technical overview of how PC-based software communicates with Honda ECUs for real-time datalogging.
NVSRAM Technical Reference
Technical overview of NVSRAM (Non-Volatile Static RAM), its types, and its suitability for ECU tuning and real-time prog...
OBD0 CN3 Serial Port Reference
Technical overview of the OBD0 ECU CN3 serial port, highlighting its functionality and pinout compatibility with OBD1 CN...
OBD0 ECU ROM Map Conversion Formulas
A directory of conversion formulas for OBD0 ECU ROM maps, including scaling factors for RPM, fuel, ignition, and VTEC pa...
OBD1 8-Bit Low-Cam RPM Scaling
Technical guide on converting 8-bit hex values from OBD1 ECU low-cam tables into readable RPM values.
OBD1 ECU: Auto to Manual Conversion
Technical guide for converting OBD1 Honda ECUs between automatic and manual configurations via resistor board modificati...
OBD1 P13 ECU: Auto to Manual Conversion
Technical guide for converting an automatic P13 ECU (Prelude H22A) for use with a manual transmission.
OBD2 P5M ECU Automatic to Manual Conversion
Convert an OBD2 P5M ECU from automatic to manual transmission by relocating the 0-ohm SMD resistor.
OBD2B ECU Reference
Technical overview of the OBD2B ECU generation used in 1999–2000 Honda Civic models and its connector compatibility.
P07 OBD1 ECU Reference (Civic VX)
Technical analysis of the P07 Honda Civic VX OBD1 ECU, featuring unique dual-processor architecture for lean-burn contro...
P0A OBD1 ECU Reference (Accord EX)
Technical reference for the P0A OBD1 ECU, found in 1994–1995 Honda Accord EX models (F22B engine).
PGMFI SourceForge Repository
An overview of the PGMFI SourceForge repository, hosting essential open-source tools for Honda ECU development and tunin...
PP5 ECU Reference (Rover/Honda)
Technical overview of the PP5 Rover/Honda ECU series, exploring its origins in the Rover-Honda partnership and compatibi...