The Toyota 4S-FE engine is a 1.8L inline-four from the legendary S-series family, common in 1990s models like the Corona, Carina, and Mark II. Because it shares its architecture with the more famous 3S-FE, many of its ECU pinout abbreviations and wiring logics are identical.
To read codes: jump TE1 to E1 with ignition ON, count CEL flashes. 4s-fe ecu pinout
| Pin | Wire Color | Function | Signal Type | Voltage/Note | | :--- | :--- | :--- | :--- | :--- | | C1 | White | Distributor NE+ (Crank angle) | AC sine wave | 0.5V – 5V depending on RPM | | C2 | Red | Distributor NE- (Sensor ground) | 0V | Shielded wire ground | | C3 | Blue | Distributor G1 (Cam position) | AC sine wave | TDC Cylinder #1 | | C4 | Yellow | Distributor G2 (Cam position) | AC sine wave | TDC Cylinder #4 | | C5 | (Empty) | N/A | N/A | N/A | | C6 | Violet | Air Conditioning (A/C) Request | +12V (AC ON) | Tells ECU to raise idle | | C7 | Light Green | Power Steering Oil Pressure Switch | Ground (when turning) | Idle-up signal | | C8 | Black | Diagnostic Port (TE1) | Ground via diag box | Jumper TE1 to E1 for codes | | C9 | White-Black | Diagnostic Port (E1) | Chassis ground | Common diagnostic ground | | C10 | Black-Red | VSV (EGR or Purge) | Ground switched | Emission control | | C11 | Red | Electric Fan Relay | Ground switched | Turns on radiator fan | | C12 | Pink-Blue | Speed Sensor (SPD) | 5V square wave | From combination meter | | C13 | (Empty) | N/A | N/A | N/A | | C14 | Red-Blue | +12V Main (IG SW) | +12V (Key ON) | Wakes up the ECU | The Toyota 4S-FE engine is a 1
Keep this article bookmarked, print the pinout chart, and tape it to your toolbox. When your 1991 Corona won’t start on a rainy morning, you will thank yourself. Plug C (14 pins) – Ignition, Diagnostic &