Ultimate Toyota 4S-FE ECU Pinout Guide: Wiring, Diagrams, and Troubleshooting
If you cannot find a specific 4S-FE diagram, the 3S-FE wiring from the same year and chassis is almost identical in pin assignment. 4s-fe ecu pinout
For the most accurate results, using a Toyota break‑out‑box and hand‑held tester is recommended to read ECU input/output values directly . Ultimate Toyota 4S-FE ECU Pinout Guide: Wiring, Diagrams,