3s-fe Ecu Pinout Pdf May 2026

Draw the connectors. Count the pins. Note that Toyota ECUs often have missing pins—this is normal.

Unplug the coolant temp sensor. Touch one multimeter probe to the sensor connector terminal and the other probe to an ECU pin. When the buzzer sounds, you have found THW. Mark it. 3s-fe ecu pinout pdf

Turn the ignition off. Find the thickest white-red wire (BATT). It should have 12V constant. Find the thick brown or white-black wires (E01, E02). These are high-current grounds for injectors. Draw the connectors

Do you have a specific 3S-FE pinout question? Leave the year and model in the comments below (or on your favorite forum), but always verify community advice against a factory PDF. Unplug the coolant temp sensor

Multimeter (with continuity beeper), 12V test light, a notebook, and an FSM for resistance values.

While the 3S-FE is not as performance-oriented as its big brother, the 3S-GE, it is a reliable and durable powerplant. However, age degrades wiring. Corrosion sets in, connectors crack, and sensors fail. Without a , you are essentially navigating a dark room without a flashlight.

| Pin | Code | Function | Wire Color (Typical) | | :--- | :--- | :--- | :--- | | A1 | +B | Main EFI Relay Power | Black-Red | | A2 | BATT | Constant 12V Memory | White-Red | | A3 | E1 | Power Ground | Brown | | A4 | IGT | Igniter Trigger Signal | White | | A5 | NE+ | Distributor Crank Signal | Black | | A6 | G1 | Distributor G1 Signal (Cam) | Blue-Red | | A7 | THW | Water Temp Sensor | Green-Blue | | A10 | STA | Starter Signal | Black-White |