Explore the whole catalog.
Search every article and filter by category, OBD generation, engine family, chassis and more. Type to reshape the results.
5050s VTEC Conversion Fix
Troubleshooting and installation guide for using 5050s components in Honda VTEC conversion circuits to resolve MIL code...
66k Assembler Docs
Here you can find all the documentation on the Oki 66K achitecture that we have been able to find. If it isn't attached...
Check Sum
A Checksum is a very basic form of error checking. A checksum is calculated by adding the values of a ROM together, with...
D1780
Technical datasheet and specifications for the NEC 2SD1780 transistor used in Honda ECU hardware circuits.
ECU Conversion Guide: 02D01980-1500 Board
Hardware modification guide for converting the 02D01980-1500 Honda ECU board, including components required for VTEC and...
ECU Definition Codes
A reference table of Honda and Acura OBD0, OBD1, and OBD2 ECU part numbers, their markets, and corresponding code design...
Hex2 Bin
You can convert Hex Files to Bin Files using hex2bin (also available as an attachment to this page) Attachment: Modify:...
High Cam
in a VTEC motor, the High Cam is used at higher RPMs. This Cam Shaft is generally optimized for power and higherRPMs.
IACV Circuit Fix - R58 and R59: Low Idle
A detailed troubleshooting and repair guide for the Idle Air Control Valve (IACV) circuit on Honda OBD1 ECUs, specifical...
Intel8051
for all you could want to know and a great tutorial, go to http://www.8052.comAny 8051 assembler will work fine for codi...
Low Cam
In a VTEC motor, the Low Cam is used at low RPMs. Generally, this Cam Shaft is optimized for fuel economy and a smooth i...
Multiprocessor Mode
MULTIPROCESSOR COMMUNICATIONS In applications where multiple controllers jointly perform a task, the master controller m...
Nico Analyze
Author: XDEep first thanks to nico for a great tool. the mishap im talking about is when you drag the scrollbar up and d...
OBD0 Oki 83C154 ROM Dumping Guide
Technical guide for dumping the internal ROM contents of an Oki 83C154 microcontroller, used in certain OBD0 ECUs.
OBD0MPFI
There is a very distinct family of ECUs found in 8891ish OBD0 hondas. The main characteristics of this family: Oki80 C15...
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...
OBD1 Oki 66207 Reader (PLCC68)
Technical guide for dumping the internal ROM contents of a PLCC68 Oki 66207 microcontroller using a custom reader interf...
OBD1P08 Auto Manual
Technical guide for converting automatic Honda P08 OBD1 ECUs to manual transmission configurations by modifying internal...
OBD2 Oki66507 Reader Nico
Technical guide to building a hardware dumper for reading internal memory from Oki 66507 microcontrollers in Honda OBD2...
P04
The P04 came in European cars. I'm not sure which years or models, so someone fill this in. They look nearly identical i...
P06
P06 9295 OBD1 Civic DX (D15B SOHC nonvtec) (Thanks Katman!) Thanks Katman: !P06top.jpg Attachment: Modify: Size: Date: W...
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...
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.
P0A OBD1 ECU Reference (Accord EX)
Technical reference for the P0A OBD1 ECU, found in 1994–1995 Honda Accord EX models (F22B engine).
P12
9295 Prelude S F22A1 Attachment: Modify: Size: Date: Who: Comment: : : : : : :
P1J
Overview of the 96-00 UK Honda Civic D14 ECU, covering its compatibility and VTEC conversion potential.
P1K
Overview of the 96-00 UK Honda Civic D14 ECU, covering its compatibility and VTEC conversion potential.
P39
P39 9295 OBD1 JDM PRELUDE BB4 DOHC NonVTEC(F22B) Attachment: Modify: Size: Date: Who: Comment: : : : : : :
P51
9293 OBD1 JDM Ascot Innova 2.3l SiZ H23A CC4 DOHC nonvtec Attachment: Modify: Size: Date: Who: Comment: : : : : : :
P61
P61 9293 OBD1 USDM GSR B17A DOHC VTEC m66207215 Attachment: Modify: Size: Date: Who: Comment: : : : : : :
P71
P71 9295 OBD1 Integra (d16a nonvtec) Attachment: Modify: Size: Date: Who: Comment: : : : : : :
P73
P73 9600 OBD2 Integra TypeR (JDM & USDM) Scan (Thanks Katman!): scan Attachment: Modify: Size: Date: Who: Comment: : : :...
P91
P91 9295 OBD1 JDM Civic Coupe (SOHC VTEC 1.6) How to identify: !P91identify.jpgScan (Thanks Katman):%%% !P91top.
PE7
the PE7 came on 8587 EDM/USDM Civic/CRX Si (EW3/EW4 Vacuum advance) cars. Thanks to Mark Lamond for the scans.
PG7
PG7 : 8687 Integra (D16A1 vacuum advance) PG7 : 8889 Integra (D16A1 electronic advance) Note: The bastards at honda desi...
Pgmfi D51
blundar modified a dasm he found, D51, to support the A5 instruction as is peculiar on the Oki 8XC154 MCUs.
PH3
THe 8889 Accord OBD0 B20A ECU uses an Electronic Advance distributor. It has an External 27c256 ROM and is oki 80c154 ba...
PJ0
The A20A 8689 Accord/Prelude PJ0 ECU had many revisions in different countries. Some of them will lack an O2 sensor or E...
PJ1
PJ1 : 8587 EDM Integra 1.6i16, CRX MK1 1.6i16 Thanks to Mark Lamond for the scans (EDM) Attachment: Modify: Size: Date:...
PK2
Prelude OBD0 B20A ECU. Electronic Advance. External 27c256 ROM. oki 83c154 based pk2 ECU photo.: I posted the Options Cl...
PL2
PL2 : 8?88+ Acura/Rover V6 (C25/C27) Attachment: Modify: Size: Date: Who: Comment: : : : : : :
PM5
PM5 8891 Civic base model/CRX DX (DPFI D15b) There were two distinct styles of this ECU. One features an 83C154 MCU, one...
PM9
Essentially a PM5The PM5 + PM9 are essentially the same ECU. I think one may have been for the 4 speed and one the 5 spe...
PP5 ECU Reference (Rover/Honda)
Technical overview of the PP5 Rover/Honda ECU series, exploring its origins in the Rover-Honda partnership and compatibi...
PR5
PR5 : 9091 JDM Integra ZXi (1.6 SOHC) This is the JDM equivalent of the USDM D16A6. Attachment: Modify: Size: Date: Who:...
PS9
PS9 : 9091 USDM Civic EX (1.6L SOHC usually auto) The PS9 is identical to a PM6 with the addition of the circuitry to co...
PS9 Auto Manual
Remove R62,R64,R66 right by the center divider to turn an auto ECU into a 5 spd. JDM ECUs also require the addition of B...
PT3
PT3 9093 OBD1 USDM Accord SOHC nonvtec F22A1 This ECU shares the shares the same PC board with the EDM PT5 Accord ECU (0...
PT5
Analysis of the PT5 EDM Honda Accord OBD1 ECU, covering its shared PCB architecture with other Accord units.
Remove A Knock Sensor
Removing the knock detection is simple: Resolder R118 and R119 into R142, 143. Then, Remove R101 (optional).
Replacing M5128 SRAM with DS1220 NVSRAM
Technical guide for upgrading a 2K SRAM chip in an OBD0 Honda ECU to a DS1220 NVSRAM for non-volatile memory retention.
VTEC Conversion Guide: "1720" ECU Boards
Technical guide for converting non-VTEC "1720" Honda ECU boards to support VTEC operation, including component lists and...
XE5
8891 (dates questionable?) Mugen Race platform (ZC) The XE5 code is derived from the PM7 specifically, the PM70330 that...
02D011F0-1500
Hardware modification guide for converting non-VTEC "11F0" Honda ECU boards to VTEC, including necessary component addit...
Automatic to Manual ECU Conversion
Overview of converting automatic Honda ECUs for manual transmission use through software or hardware modifications.
Get Rid Of Cruise Control Upshift Light
All you need to do is remove R135. When I modify some P05 ecus I would sometimes get a solid Cruise control light when u...
Honda OBD1 ECU Reference (1992–1995)
Technical overview of OBD1 (1992–1995) Honda Engine Control Units, including popular ECU models and their applications.
Non-VTEC to VTEC ECU Conversion
Guide for converting non-VTEC Honda ECUs to support VTEC operation, outlining necessary hardware modifications.
OBD1 ECU Code Compatibility Guide
Guide to OBD1 ECU code compatibility, detailing VTEC requirements, sensor exclusions (O2/Knock), and regional (USDM/JDM/...
Found a gap or an error? Sign in with Discord to suggest an edit (reviewed before it goes live), or join the community on Discord and GitHub.
Join the Discord →