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PT3 ECU Technical Reference

Technical reference for the OBD1 PT3 ECU used in 1990-1993 USDM Honda Accord models with the F22A1 engine.

Intermediate 3

carotman Author
acclude Author

The PT3 ECU is an OBD1 engine control unit utilized in 1990–1993 USDM Honda Accord vehicles equipped with the SOHC non-VTEC F22A1 engine. This unit shares the same printed circuit board (PCB) architecture as the EDM PT5 Accord ECU (part number 02D01190-1504).

PCB Overview

The PT3 architecture is consistent across various regional variants. The following images detail the component layout and board design.

Front view of PT3 ECU PCB
Top view of the PT3 PCB assembly
Bottom view of PT3 ECU PCB
Bottom view of the PT3 PCB assembly
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Variant Specifications

The PT3 ECU was produced in several configurations depending on transmission type and regional emissions requirements.

Variant Application Transmission
PT3-A23 1991 USDM EX Accord Manual
PT3-A54 1992 Canadian LX Accord Automatic

Note

The PT3-A23 variant utilizes the OKI 66911 processor, 38256 memory, and 74HC373 latch ICs.

Component Gallery

![1992 Canadian LX Accord Auto](PT3_A54.jpeg)
*PT3-A54 variant for automatic transmission*
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![1991 USDM PT3-A23 EX Accord Manual](USDM-PT3-Manual-front.jpg)
*Front view of the PT3-A23 manual transmission ECU*
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![1991 USDM PT3-A23 EX Accord Manual](USDM-PT3-Manual-back.jpg)
*Back view of the PT3-A23 manual transmission ECU*
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![PT3-A23 internal components](USDM-PT3-Manual-chips-resistors.jpg)
*Detail of OKI 66911, 38256, and 74HC373 IC placement*

Applies to

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Cars 1 link

Honda

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Model Accord
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