Connector B (B1–B13)
Connector A (12P) Connector B (16P) Connector C (26P) [ o o o o o o ] [ o o o o o o ] [ o o o o o o o o o o o o ] [ o o o o o o ] [ o o o o o o ] [ o o o o o o o o o o o o o o ] 12 11 10 9 8 7 16 15 14 13 12 11 26 25 24 23 22 21 20 19 18 17 16 15 6 5 4 3 2 1 10 9 8 7 6 5 4 14 13 12 11 10 9 8 7 6 5 4 3 2 1
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These pins deliver battery voltage to the computer and provide the chassis grounds necessary to complete the electrical circuits.
The 4S-FE is a 1.8L inline-4 engine produced by Toyota, used in various models such as the Camry, Corolla, and Solara. The ECU (Engine Control Unit) for this engine is a complex computer that controls various engine functions, including fuel injection, ignition timing, and emissions.
If you are working on a swap or troubleshooting, the most reliable way to identify pins is to look for the (PCB) next to the connector pins. Common 4S-FE ECU Pin Abbreviations & Functions 4s-fe ecu pinout
You need a 4S-FE specific O2 sensor (1-wire or 4-wire depending on your ECU version). Using the wrong O2 will keep the ECU in open loop and destroy fuel economy.
Informs the ECU that the throttle is fully closed.
Signals for idle switch (IDL) and variable throttle angle (VTA). Oxygen Sensor Feedback from the O2 sensor; "HT" is for the sensor heater. STA Starter Signal
Signal from the Throttle Position Sensor (TPS).
Proper voltage and grounding are critical to prevent ECU burnout or erratic engine behavior. Function / Description Expected Voltage Main Power (Switched via EFI Relay) 12V (Key ON) +B1 Secondary Main Power 12V (Key ON) BATT Constant Battery Power (Memory Backup) 12V (Always Hot) IGSW Ignition Switch Signal 12V (Key ON / Crank) E1 Engine Ground (Chassis Connection) E2 Sensor Ground (Internal ECU Ground) E01 / E02 Injector & Power Grounds Ignition and Fuel Injection Pins Connector B (B1–B13) Connector A (12P) Connector B
If your wires look faded or have been cut, use this cross-reference:
You only need from the 3S-FE to make a standalone run:
The CarTechnology forum has archived threads specifically requesting 4S-FE pinouts for the ST190 Corona. Toyota 4S-FE ecu pin out please - Printable Version
Always verify pinout with a factory wiring diagram for your exact (e.g., 89661-1A630, 89661-20220). Wire colors and pin functions changed between model years, transmissions, and markets.
: Often contains main power (+B, BATT), grounds (E1, E01), and primary sensor inputs (PIM, THW). search results show some potential sources
The ECU reads these pins to determine engine load, temperature, and speed to calculate fuel delivery and spark timing.
| Pin # | Signal Name | Description | | --- | --- | --- | | 1 | EGT | Engine Ground | | 2 | IGT | Ignition Timing Signal | | 3 | IGF | Ignition Feedback Signal | | 4 | GND | Ground | | 5 | +B | Battery Voltage | | 6 | THA | Throttle Angle Sensor ( TPS) | | 7 | ODO | Odometer Signal | | 8 | ISC | Idle Speed Control | | 9 | SFT | Shift Solenoid (Automatic Transmission) | | 10 | L | Fuel Pump Relay | | 11 | W | Fuel Pump Monitor | | 12 | RCO | Resistance (Resistor) Check Output | | 13 | NE | Engine Speed Sensor (CKP) | | 14 | NTC | Coolant Temperature Sensor (ECTS) | | 15 | AFS | Air/Fuel Sensor (Oxygen Sensor) | | 16 | A/F | Air/Fuel Mixture Control | | 17 | Rx | Serial Communication Receive | | 18 | Tx | Serial Communication Transmit | | 19-26 | - | Not Used |
Because the 4S-FE was manufactured across multiple generations, .
| Pin | Type | Signal Name | Function | |:---:|:---:|:---:|:---| | 3 | Input | | Engine Coolant Temperature Signal | | 5 | Input | THA | Intake Air Temperature Signal | | 4 | Input | PIM | Intake Manifold Pressure Signal (for some markets) | | 7-8 | Input | VTA / VCC | Throttle Position Sensor Signal | | 9 | Input | NE | Crankshaft RPM Signal (from distributor) | | 21 | Input | NE (Alt.) | RPM Signal (alternate pin) | | 10 | Input | OX | Oxygen Sensor (Lambda) Signal | | 23 | Input | KNK | Knock Sensor Signal | | 16 | — | E2 | Sensor Ground (return for sensors) | | 24 | Ground | E1 | Computer Ground (main ground) |