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USB-to-TTL Serial Converter Guide (`FTDI` & CP2102)
How to configure and troubleshoot USB-to-TTL serial converters (such as FTDI or CP2102 chips) for reliable ECU dataloggi...
Australian Domestic Market (OzDM) Vehicle Specifications
Technical overview of Australian Domestic Market (OzDM) Honda vehicle specifications and ECU configurations.
check8 8-Bit ROM Checksum Utility
A command-line utility for verifying and correcting 8-bit ROM checksums during firmware compilation.
Honda ECU Serial Datalogging (`CN2` TTL Header)
Learn how Honda OBD1 ECUs communicate with tuning laptops via serial TTL signals (CN2 header), including pinouts, settin...
Tuning Honda ECUs for Smog and Emissions Inspections
A comprehensive guide on adjusting fuel and ignition maps in your Honda ECU ROM to pass vehicle tailpipe emissions and s...
AC Cut Routine
Author: evo (61.88.2.177) Date: 030403 22:15 After much thought, ive decided to share my AirConditioner Cutoff routine.
Auto Or Manual
A hardware/software interaction will determine whether a program in an ECU behaves as a manual or auto.
Back Links Functionality
An overview of the Back Links functionality used to identify pages that link to or reference the current technical artic...
Basic Concepts of Honda Engine Management
An introductory guide to electronic engine management concepts for Honda enthusiasts, covering air, fuel, spark, and sen...
Calendar Plugin
Technical overview of the Calendar Plugin functionality for wiki page management.
Chipping the JDM OBD1 P30 ECU
Hardware modification guide for socketing, chipping, and converting JDM square-case OBD1 P30 ECUs to manual transmission...
Like Pages Reference
An overview of the Like Pages feature, which identifies and links pages sharing common initial or final terminology with...
`29C256`
the ATMEL AT29C256 chip is the de facto FLASHROM chip in use. It uses a 5V programming voltage, can be erased repeatedly...
02D011F0-1500
Hardware modification guide for converting non-VTEC "11F0" Honda ECU boards to VTEC, including necessary component addit...
1-Wire VTEC Conversion
Technical overview of the 1-wire VTEC ROM codebase, which utilizes the automatic transmission lockup solenoid to control...
1991 Honda PM6 ECU Reference
Technical reference for the 1991 Honda PM6 ECU, covering idle target configuration and onboard diagnostic LED troublesho...
1991 PM6 ECU Diagnostic LED (CEL) Blinking Routine
Technical explanation of the diagnostic LED/CEL blink routine inside the 1991 OBD0 PM6 ECU codebase.
1991 PM6 ECU Target Idle Routine Analysis
Technical analysis of the 1991 PM6 ECU target idle routine, including memory address locations and code structure compar...
1991 PM7 ECU Technical Reference
Technical reference for the 1991 PM7 ECU, including idle target configuration and sensor management.
27C256 EPROM Specifications
Technical specifications, pinout diagrams, and speed requirements for the 27C256 EPROM chip used in OBD0 and OBD1 Honda...
28C256 EEPROM Pinout and ECU Compatibility
Technical specifications, pinout mapping, and socket modification instructions for using the 28C256 EEPROM chip in stand...
5050s VTEC Conversion Fix
Troubleshooting and installation guide for using 5050s components in Honda VTEC conversion circuits to resolve MIL code...
515X High Side Switch
Honda uses a 5 pin high side switch in a lot of their OBD1 and OBD2 ECUs to control solenoids like auto trans and VTEC s...
74HC373 Octal Latch IC
Technical overview of the 74HC373 octal latch IC, commonly used for external ROM interfacing in Honda ECU hardware.
8051 and Oki 66k Carry Bit (C) Reference
An overview of the carry bit (C) functionality within 8051 and Oki 66k architectures, focusing on arithmetic overflow tr...
82C55 Programmable Peripheral Interface
Technical specifications and pinout mapping for the OKI MSM82C55A Programmable Peripheral Interface (PPI) chip used in H...
A/C Thermostat Switch Bypass
Guide for jumping the A/C thermostat switch during A/C system troubleshooting or installation.
A143 Transistor Specifications and Replacements
Technical reference for the A143 transistor used in Honda ECU circuits, including specifications and verified component...
Acura Brand History and Overview
Overview of the Acura brand history and its evolution within the Honda automotive ecosystem.
Acura Integra PR4 OBD0 ECU Pinouts
Pinout information and wiring reference for the OBD0 Acura Integra PR4 ECU (B18A1 engine).
Adding 1-Wire VTEC Control to OBD0 ECUs (PM6)
Hardware modification guide to adding 1-wire VTEC control to OBD0 Honda ECUs by populating unused automatic transmission...
Adding a Knock Sensor to a Honda ECU
Hardware modification guide for adding a knock sensor to a Honda P75/P72 ECU board.
Adding IAB Control to an OBD1 P28 ECU
Hardware modification guide to add Intake Air Bypass (IAB) secondary runner controls to an OBD1 Honda P28 Civic ECU.
Adding Knock Sensor Circuitry to OBD1 ECUs
Step-by-step hardware guide for adding a knock sensor circuit to non-equipped Honda OBD1 ECUs using specific component m...
Air-Fuel Ratio (AFR) Guide for Honda Tuning
An introduction to Air-Fuel Ratio (AFR) in internal combustion engines, explaining stoichiometric targets, rich vs. lean...
Analog-to-Digital Conversion (ADC)
An overview of Analog-to-Digital Conversion (ADC) in automotive ECU applications, including resolution and reference vol...
Application Programming Interface (API) Reference
An Application Programming Interface (API) is a set of functions within a library or DLL that allows software to perform...
ASM662 Assembler and Disassembler
ASM662 is an assembler and disassembler tool for Oki 66201, 66207, 66301, and NEC 66911 microcontrollers used in various...
Atmel AT29C010 Flash ROM
Technical overview of the Atmel AT29C010 1Mbit (128kb) FLASH-ROM chip, including its application in ECU tuning and pinou...
Atmospheric Pressure
An overview of atmospheric pressure and its significance in engine management, with reference unit conversions.
Atmospheric Pressure (PA) Sensor Reference
The atmospheric pressure (PA) sensor measures ambient air pressure to adjust fuel mixtures for altitude and weather-rela...
Atmospheric Pressure (PA) Sensor Technical Reference
Technical guide to the Atmospheric Pressure (PA) sensor in Honda ECUs, explaining its role in altitude compensation and...
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...
Automatic to Manual ECU Conversion
Overview of converting automatic Honda ECUs for manual transmission use through software or hardware modifications.
Automatic to Manual Transmission ECU Conversion
Convert an automatic transmission ECU to manual transmission operation by removing specific resistors and adding a jumpe...
Automatic Transmission Lockup Solenoid
An overview of the Automatic Transmission Lockup Solenoid function, ECU pinout, and common repurposing for OBD0 Honda ve...
BAR (Unit of Pressure)
An overview of the BAR unit of pressure measurement and its relationship to atmospheric pressure and PSI.
Batronix USB Programmer Technical Guide
Technical overview and operational guidelines for using the Batronix USB Programmer to read and write ECU EPROM and Flas...
C144 NPN Switching Transistor
Technical specifications and replacement guide for the C144 NPN switching transistor used in Honda ECU circuits.
C2785 NPN Switching Transistor
Technical specifications and compatible replacements for the C2785 high-speed NPN switching transistor used in Honda ECU...
Camshaft Profile Fundamentals
An overview of camshaft profiles, defining the fundamental measurements of cam lift, duration, and overlap for internal...
Check Engine Light (CEL)
An explanation of the Check Engine Light (CEL), its function, and how to retrieve diagnostic trouble codes.
Chipping 1988-1989 OBD0 ECUs
Technical procedures for socketing and chipping 1988-1989 OBD0 Honda and Acura ECUs equipped with internal-ROM OKI M83C1...
Chipping OBD1 Small-Case ECUs
Step-by-step instructions for socketing and chipping small-case Honda OBD1 ECUs, commonly found in JDM and some European...
Chipping OBD2 Honda ECUs (OKI 66507 / 66P507)
Hardware guide for chipping OBD2 Honda ECUs by replacing the OKI 66507 processor with a programmed 66P507 OTP microcontr...
Chipping the OBD0 PM6 ECU (1988–1991 Civic/CRX Si)
Step-by-step hardware guide to chipping the OBD0 PM6 ECU (1988–1991 Civic/CRX Si) to accept external EPROMs and custom t...
Clamping Diode Installation and Selection
Learn how to protect sensitive ECU circuitry from voltage spikes caused by inductive loads like solenoids using a clampi...
Combustion Chamber
An overview of the engine combustion chamber, its role in the ignition process, and its influence on engine performance.
Contributing to Hondabase Documentation
Learn how to contribute to the Hondabase knowledge base by utilizing the Edit Text feature available on all technical do...
Converting Intel HEX Files to Binary (BIN)
Learn how to convert Intel HEX files to binary (BIN) format for ECU tuning and ROM programming using the hex2bin utility...
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