Decoding the Heart of the MR2 and Camry: The Significance of the Toyota 3S-FE ECU Pinout
Constant 12V power from the battery (used for memory/diagnostic codes).
Receives 12V from the EFI Main Relay when the ignition switch is ON. Constant Battery Power 3s-fe ecu pinout pdf
| Pin | Wire Color | Signal | Description | |------|------------|--------|-------------------------------| | B1 | G-R | VTA | Throttle position sensor signal | | B2 | G-Y | VS | Air flow meter signal (Karman vortex) | | B3 | G | E2 | Sensor ground | | B4 | B-Y | THW | Engine coolant temp sensor | | B5 | L-B | THA | Intake air temp sensor | | B6 | R-L | KNK | Knock sensor (if equipped) | | B7 | W | OX1 | Oxygen sensor (front) | | B8 | B-W | FC | Fuel pump relay control | | B9 | Y-R | ACT | A/C request signal | | B10 | L-R | M-REL | EFI main relay control |
Before splicing any wires, you must identify the specific generation and market origin of your 3S-FE engine. Toyota updated the electronics, ignition systems, and emissions controls multiple times throughout the engine's production run. 1. Generation 1 & 2 (Late 1980s to Early 1990s) Camry (V20), Celica (T160/T180). Decoding the Heart of the MR2 and Camry:
Because component pinouts vary by year and destination market (JDM, USDM, EUDM), relying on a single generic image can result in frying your ECU. Follow these steps to source a verified PDF manual:
For a Toyota 3S-FE engine control unit (ECU), the most informative feature is a complete terminal assignment breakdown that links electrical pins directly to specific sensors and actuators. Because the 3S-FE engine was utilized across different vehicles (like the Toyota RAV4, Camry, and Celica) and production years, pinouts vary depending on the specific model and whether the car uses an OBD1 or OBD2 management system Because component pinouts vary by year and destination
Note: Always verify your specific ECU part number against the document you are referencing before cutting or probing wires to avoid damaging the electrical system. particular year 3S-FE ECU Pinout for Toyota RAV4 | PDF | Engines - Scribd