Toyota 4afe Ecu Pinout Guide

The pinout below covers the most common found in the 1992–1995 Corolla/Geo Prizm (AE101 chassis).

: Sensor ground (return) for the TPS, coolant, and intake air sensors. Ignition System toyota 4afe ecu pinout

This pinout is based on the 1993–1995 Toyota Corolla DX/LX (1.6L 4AFE) with manual or automatic transmission. The pinout below covers the most common found

connector setup found in mid-90s models like the Corolla AE101: ECU Pinout Overview Description Battery Power Constant 12V power from the battery for memory. Switched Power 12V power from the EFI Main Relay when the ignition is ON. Engine Ground Main chassis ground connection for the ECU. Power Ground Ground for heavy-load components like injectors. Injector Signals Pulse signals sent to the fuel injectors. Ignition Trigger Signal sent from the ECU to the igniter to fire the coil. Ignition Feedback Confirmation signal sent from the igniter back to the ECU. Sensor Voltage Regulated 5V supply for sensors like the MAP/MAF and TPS. Throttle Signal Input from the Throttle Position Sensor (TPS). MAP Sensor Intake manifold pressure signal used for fuel calculation. Water Temp Input from the Engine Coolant Temperature (ECT) sensor. Input from the Intake Air Temperature (IAT) sensor. Oxygen Sensor Signal from the O2 sensor for air-fuel ratio monitoring. Starter Signal Input signal to tell the ECU the engine is cranking. Speed Signal Input from the vehicle speed sensor (VSS). Check Engine connector setup found in mid-90s models like the

– 4AFE ECUs from 1990–1994 are notorious for leaking electrolytic capacitors (C312, C314). This eats PCB traces, especially the injector drivers and IGt circuit.