Pinout | 4s-fe Ecu

Below are the critical signals and pins typically found on 4S-FE engine control units, categorized by their system role:

If your harness colors don't match the diagrams you find online, unscrew the ECU casing and look at the bottom of the PCB. Toyota almost always (like "BATT", "E1", "PIM") directly onto the board near the pins. This is the "gold standard" for ensuring you don't fry your computer during a custom wiring job. If you'd like, let me know: The exact car model and year (e.g., 1994 Toyota Corona) The part number on your ECU (e.g., 89661-xxxxx) The connector count (Is it 2-plug or 3-plug?)

5V reference power supplied by the ECU to sensors like the TPS. Throttle Position 4s-fe ecu pinout

Clearing codes: Remove the EFI fuse (15A) for 30 seconds or disconnect battery.

Toyota 4S-FE engine, part of the S-family, was commonly found in Japanese market vehicles like the Corona, Carina, and Mark II Below are the critical signals and pins typically

If your wires look faded or have been cut, use this cross-reference:

While specific wire colors can vary by vehicle year, the terminal abbreviations remain consistent across Toyota platforms. ⚡ Power and Ground If you'd like, let me know: The exact car model and year (e

Important notes and checks