Toyota 4afe Ecu Pinout < POPULAR >

Measure the voltage between pin VC and pin E2 . It must read a steady 4.9V to 5.1V. If this voltage is missing or pulled down to 0V, a shorted sensor (such as a bad MAP or TPS) is dragging down the internal ECU power supply.

| | Common Pin(s) | Function | | :--- | :--- | :--- | | +B (Battery) | A11, A12, etc. | Constant battery voltage (12V+) for ECU memory | | +B1 | B3, B11 | Constant battery voltage (12V+) for ECU memory | | MREL (EFI Main Relay) | A? | ECU output to activate the EFI main relay | | E1, E01, E02, E2 | A13, A14, A26, B9, etc. | ECU ground reference point (connects to chassis ground). Notably, the brown wire (E1) is the primary ground for the ECU. | toyota 4afe ecu pinout

On OBD-I 4A-FE systems, locate the "Diagnostic" box under the hood. Use a paperclip to jumper pins TE1 and E1 . Turn the ignition key to ON. Count the flashes of the Check Engine Light on the dashboard to read manual fault codes. Measure the voltage between pin VC and pin E2

Always verify wire colors with a specific wiring diagram for your exact year and region (USA vs JDM vs Euro) as Toyota changed wire colors frequently. | | Common Pin(s) | Function | |