4s-fe Ecu | Pinout

This is constant 12V power from the battery used for memory. If this wire is cut, your car may run but will lose "learned" idle data every time you turn it off.

The 4S-FE uses a simple diagnostic system. Jump pins (B11) to E1 (A3) with the engine off. Turn key ON. The check engine light (pin A15 or B12) will flash codes. 4s-fe ecu pinout

| Pin | Wire Color | Function | Signal Type | Voltage/Note | | :--- | :--- | :--- | :--- | :--- | | B1 | Gray | Throttle Position Sensor (VTA) | 0.3 – 4.8V | Closed = 0.3V / WOT = 4.8V | | B2 | Green | TPS Reference Voltage (VC) | 5V ± 0.1V | Supplied by ECU | | B3 | Brown | TPS Ground (E2) | 0V | Sensor ground | | B4 | Red-Yellow | Intake Air Temp (THA) | 0.5 – 3.5V | Cold = high voltage | | B5 | Blue-Black | Engine Coolant Temp (THW) | 0.2 – 3.5V | Hot engine = ~0.5V | | B6 | (Empty) | N/A | N/A | N/A | | B7 | Black-Blue | MAP / VAF Sensor (PIM) | 1.5 – 4.5V | Idle = 1.5V / WOT = 4.0V | | B8 | Green-Red | MAP/VAF 5V (VCC) | 5V | Sensor power | | B9 | White-Black | MAP/VAF Ground (E2) | 0V | Sensor ground | | B10 | Black-Red | Idle Air Control Valve (RSC) | +12V | IACV coil #1 | | B11 | Black-Yellow | Idle Air Control Valve (RSO) | +12V | IACV coil #2 | | B12 | (Empty) | N/A | N/A | N/A | This is constant 12V power from the battery used for memory

We will assume the (Plug A = 16 pins, Plug B = 12 pins, Plug C = 14 pins). Looking at the ECU with the harness connector facing you and the locking clip facing up: Jump pins (B11) to E1 (A3) with the engine off