| Pin | Code | Function | Wire Color (Typical) | | :--- | :--- | :--- | :--- | | | +B | Main EFI Relay (Power) | Yellow/Red | | A2 | E1 | ECU Ground (Power return) | Brown | | A9 | STA | Starter Signal (to tell ECU you’re cranking) | Black/White | | A10 | VTA | Throttle Position Sensor (TPS) Signal | Light Green | | A11 | VC | 5V Sensor Power (for TPS & AFM) | Yellow/Blue | | A14 | THW | Coolant Temp Sensor Signal | Brown/Yellow | | A18 | IGF | Ignition Feedback (from Igniter to ECU) | White | | A20 | IGT | Ignition Timing Signal (ECU to Igniter) | Red/White | | A21 | NE+ | Distributor Crank Position Signal (+) | White | | A22 | NE- | Distributor Crank Position Signal (-) | Black |
The ECU typically uses two or three connectors. Key signals often include: Pin Type Common Labels +B, +B1, BATT Main power from EFI relay and constant battery power. Ground E1, E01, E02, E2 4s-fe ecu pinout
(sharing architecture with the 3S-FE), many terminal labels are standardized across Toyota's 1990s ECUs. If you are looking at a standard 26P-16P-12P or 26P-16P connector set, the following signals are typically in these positions: Ignition Signals : Look for (Ignition Timing) and (Ignition Feedback). Sensor Inputs : Pressure Intake Manifold (MAP Sensor signal). : Water Temperature Signal (Green-Black wire). : Intake Air Temperature (Light Green-Black wire). : Oxygen Sensor (Lambda). Power & Ground : Constant +12V from EFI Main Relay. : Switched +12V ignition power. : Main computer grounds (usually White-Black or Brown). Fuel Injection are the primary injector pulse signals. Additional Reference Manuals | Pin | Code | Function | Wire