Let's look at the wiring schematics for several common Toyota ECUs. Keep in mind that these diagrams are reference tools; they may show all possible connections for a particular ECU series, but your specific vehicle harness may not use every single pin.
use large multi-row connectors. Detailed guides are often found on enthusiast sites like Lextreme . toyota 89661 ecu pinout
The Toyota series refers to a broad range of Engine Control Units (ECUs) used across decades of vehicles, from 1980s 22RE engines to modern 1GR-FE platforms. Because the part number prefix "89661" is generic, you must identify the specific suffix (e.g., 89661-52592) and the engine model to find an accurate pinout . Common 89661 ECU Pinout Examples Let's look at the wiring schematics for several