4s-fe Ecu Pinout Site

The 1990–1997 Toyota 4S-FE ECU is a compact metal box located behind the glovebox (RHD models) or under the passenger kick panel (LHD models). It uses , often labeled:

| ECU Pin | Connect to | |---------|-------------| | A1 & A2 | 12V battery (via EFI relay, triggered by ignition ON) | | A10, A11, C11 | Engine ground (direct to battery negative) | | B6 | Fuel pump relay (ECU grounds to run pump) | | B5 | Igniter IGT input | | B1, B2, B3 | Distributor | | C1 | Coolant temp sensor | | C7 | Optional – jumper to ground for diagnostics | | C9 | Tachometer output | 4s-fe ecu pinout

He pulled the passenger kick panel. There it was: the 16-bit brain, a grey metal box stamped 89661-1A230 . Four plugs: A, B, C, and D. Sixty-two pins of silent judgment. The 1990–1997 Toyota 4S-FE ECU is a compact

: Ignition timing and feedback signals to the igniter. Four plugs: A, B, C, and D

Some early 4S-FE ECUs (pre‑1992) use 16-pin or 22-pin connectors. Always verify your specific ECU part number (printed on the white label). This guide covers the most common 3x12-pin configuration used from 1992–1997.