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4s-fe Ecu Pinout →

This is based on the 3S-FE / 4S-FE engine family with a Japanese or European market Toyota ECU (often 22-pin + 16-pin connectors).

Ignition Feedback signal from the igniter to confirm firing. Green / Blue Engine speed (RPM) signal from the distributor pickup. Light Green Pressure Intake Manifold (MAP sensor) signal. Green-Black Engine Coolant Temperature (ECT) sensor signal. Oxygen sensor signal (Lambda). Diagnostic and Auxiliary Terminals Technicians often use these pins at the Check Connector

3. Code 12 – No NE or G Signal

Symptoms: Crank, no start. Check engine light code 12. Fix: Before blaming the distributor, check continuity from pin C1/C3 to the distributor plug. The shielded wire often breaks inside the insulation near the cam timing cover. 4s-fe ecu pinout

TE1 / TE2: Diagnostic test terminals; jumping TE1 to E1 in the diagnostic box allows for reading error codes via the check engine light. W / Check Engine: Output for the dashboard warning light. SPD: Vehicle Speed Sensor (VSS) signal.

Most 4S-FE ECUs utilize a three-plug system. When looking at the ECU pins (not the wire side), the plugs are generally labeled from left to right. Plug A (26-pin): Mostly engine sensors and injectors. Plug B (16-pin): Power, ground, and ignition signals. This is based on the 3S-FE / 4S-FE

Pro tip: Always check your ECU part number (e.g., 89661-05490, 89661-2B250) before trusting any diagram. This guide covers the common 22-pin + 16-pin + 12-pin layout (Gen 2) found in most USDM 1992-1994 Camrys.

  • A1 — TPS signal (Throttle Position Sensor) — SIG
  • A2 — ECT (Engine Coolant Temp) sensor — SIG
  • A3 — IAC / ISC control (Idle Air Control stepper/solenoid) — CTRL
  • A4 — IAC ground/reference — GND/SIG
  • A5 — MAP/TP reference or vacuum sensor (on some variants) — SIG
  • A6 — Knock sensor (KS) — SIG
  • A7 — Injector #1 drive — CTRL
  • A8 — Injector #2 drive — CTRL
  • A9 — Injector #3 drive — CTRL
  • A10 — Injector #4 drive — CTRL
  • A11 — Fuel pump relay control (FP) — CTRL
  • A12 — A/C compressor cut (A/C signal) / ECU input from A/C switch — SIG

THW (Coolant Temperature): Monitors engine heat to adjust fuel trim and idle speed. A1 — TPS signal (Throttle Position Sensor) —

STA: Starter signal, informing the ECU that the engine is cranking. Troubleshooting Tips ECU Connectors Everything You Need to Know