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    Convert a Honda ECU from Automatic to Manual

    Editors note: Originally published by Adam P. on his sub-site, Change Honda ECU from Automatic to Manual. Preserved here in the forums going forward. This guide will help you identify and change or convert your automatic ecu to a manual version. Honda Manual or Automatic ECU Identification...
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    EFI 101

    This is going to be a multi-part series that will be written over the course of a couple days. It will overview of building a complete EFI system for your turbo Honda and taking it all the way from parts in a box to a high-power, running correctly machine. A basic outline of this thread...
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    Honda ECU List

    Honda ECU List This table provides details about common Honda ECUs, their common name code, the On Board Diagnostics version, and if they have native functionality to support VTEC lobe switching. The Stock Engine code column highlights what engine(s) that ECU is commonly paired with in a...
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    Honda ECU Error Codes

    Honda ECU Error Codes Here's a handy chart for pulling your ECU codes. Pulling the code is a fairly easy process. For 92+ Honda's and 94+ Acura's: Before you can start reading the CEL (check engine light) in your dash, you need to 'jump' your ecu. Locate the factory two-pin connector of...
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    ECU Pinouts

    Honda ECU Pinouts OBD 0 Pinout '88 HF/Si '90-1 DX (Std.) '90-1 HF/Si '89-92 EF8/9 SiR A1 No.1 INJ Aux INJ w/A3 No.1 INJ No.1 INJ A2 GRD w/A4 to Main Relay GRD w/A4 to Main Relay GRD w/A4 to Main Relay GRD w/A4 to Main Relay A3 No.2 INJ Aux INJ w/A1 No.2 INJ No.2 INJ A4 GRD w/A2 to...
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    Open Loop VS Closed Loop ECU Modes

    ECU Modes There are 2 main operation modes for the ECU. Open Loop OPEN LOOP - this is the mode your ECU is in until the coolant temperature and a couple other sensors get to operating values. The ECU also runs the car in open loop when you are at Wide Open Throttle (WOT) or if there is an...