Toyota 4afe Ecu Pinout [FAST]

If the engine cranks but won't start, back-probe the IGT pin while cranking. You should see a pulsing voltage. If IGT is pulsing but you have no spark, the igniter or ignition coil is bad. If IGF is missing, the ECU will cut fuel injector firing after approximately 2 to 3 seconds as a safety mechanism.

If you own a pre-1992 4A-FE, your ECU pinout will differ significantly. Do not use the pinout above for a 1989 Corolla.

| Pin | Wire Color | Signal Name | Function | | :--- | :--- | :--- | :--- | | | Purple | TACH | Tachometer Output (from igniter via ECU) | | C02 | Yellow | NSW | Neutral Start Switch (Auto only) / Clutch switch (Manual) | | C03 | Red/Black | L | Oil Pressure Warning Light (some markets) | | C04 | Black | E2 | Ground for sensors (duplicate of B13) | | C05 | Pink | M-REL | Main EFI Relay Control (ECU turns relay ON) | | C06 | Green/Red | VTA2 | TPS Closed Throttle Position Switch (IDL) | | C07 | Green | VCC2 | Secondary 5V reference (rarely used) | | C08 | - | - | Empty | | C09 | Yellow/Blue | TC | Diagnostic Communication Line (OBD-I scanner) | | C10 | Black/Red | A/C IDL | A/C Idle-Up Signal (raises idle when A/C is on) | | C11 | Red | BATT | Constant 12V for ECU keep-alive memory | | C12 | Yellow/Green | STP | Stop Light Switch Signal (brake pedal input) | toyota 4afe ecu pinout

Exclusively uses a MAP sensor for load calculation.

Oxygen Sensor signal voltage output (cycles between 0.1V and 0.9V). Diagnostic and Auxiliary Control If the engine cranks but won't start, back-probe

Working with an ECU requires caution. Here are some important warnings to keep in mind:

The signals for the distributor pickup coils (NE, G1, G2 signals responsible for RPM and crank angle detection) operate on low-voltage AC signals. Ensure these wires are shielded, and ground the shield only at the ECU side to prevent ground loops. If IGF is missing, the ECU will cut

Jumpering this pin to E1 (Ground) commands the ECU to enter diagnostic mode. The dashboard Check Engine Light will begin flashing diagnostic trouble codes (DTCs).

The pin outputs a regulated 5.0 volts. This voltage is shared directly between the MAP sensor and the TPS.

This connector handles sensors, power, and ground.

If this sensor fails, the ECU may think the engine is permanently cold (-40°C), causing it to run extremely rich.