Toyota 4afe Ecu Pinout [repack] -

Toyota 4A-FE ECU pinout is a critical technical resource for maintaining or modifying the engine management system of vehicles like the Toyota Corolla. Because the 4A-FE engine was produced for many years, pinouts vary significantly based on the specific model year and region. Key Technical Specifications Connector Configurations

Scenario: Engine Runs Rich / Black Smoke

• Probe pin A7 (VTA) – if stuck at 4V, ECU thinks throttle is wide open and dumps fuel.
• Probe pin B4 (O2) – should cycle 0.1–0.9V at idle. If stuck at 0.1V (lean) but engine is rich, O2 sensor dead or wiring to pin B4 shorted.

| Pin | Wire Color | Function | Signal Type | | :--- | :--- | :--- | :--- | | B1 | Green/Black (G-B) | Cam Angle Sensor (NE – RPM signal) | Digital (5V pulse) | | B2 | Green/White (G-W) | Cam Angle Sensor (G1 – Cylinder identification) | Digital (5V pulse) | | B3 | – | Not used | – | | B4 | Green/Orange (G-O) | Engine Coolant Temp (ECT) Sensor signal | Analog (0.5-4.5V) | | B5 | Blue/Red (L-R) | Throttle Position Sensor (VTA – Signal) | Analog (0-5V) | | B6 | Red/Yellow (R-Y) | Power Steering Oil Pressure Switch (PSPS) | On/Off (12V or 0V) | | B7 | White (W) | A/C Switch Signal (from HVAC control) | On/Off (12V) | | B8 | Black/Red (B-R) | +5V Sensor Reference Voltage (VCC) | Power (5V) | | B9 | Yellow/Green (Y-G) | Park/Neutral Position Switch (PNP – Neutral start) | On/Off (0V when in P/N) | | B10 | Brown (BR) | Manifold Absolute Pressure (MAP) Sensor signal | Analog (1.5-4.5V) | | B11 | Red/White (R-W) | Starter Signal (STA – from ignition switch) | 12V during crank | | B12 | Black/White (B-W) | Ignition Signal (IGT – from distributor) | Digital pulse | | B13 | Blue/White (L-W) | Ignition Confirmation Signal (IGF – to ECU) | Digital pulse | | B14 | Red/Green (R-G) | Throttle Position Sensor (IDL – idle contact) | On/Off (0V at idle) | | B15 | Green/Yellow (G-Y) | Vehicle Speed Sensor (SPD – from combination meter) | Digital pulse (12V square) | | B16 | Brown/Yellow (BR-Y) | Oxygen Sensor (OX – Front, if pre-cat) | Analog (0.1-0.9V) | | B17 | Brown/White (BR-W) | Oxygen Sensor Ground (EX1) | Sensor Ground | | B18 | Black/Brown (B-BR) | Sensor Ground (E2 – common return) | Ground | | B19 | Red/Black (R-B) | Battery Backup (BATT – Keep-alive memory) | Constant +12V | | B20 | Blue/Black (L-B) | Diagnostic Port (TE1) | I/O | | B21 | Red/White (R-W) | Diagnostic Port (TE2) | I/O | | B22 | Green/Black (G-B) | Diagnostic Port (VF1 – Air-fuel ratio monitor) | Analog | toyota 4afe ecu pinout

Connector Identification

The ECU typically has two physical connectors plugged into it. Toyota 4A-FE ECU pinout is a critical technical

Part 6: Wiring Color Cross-Check for OBD-II (Type 3 – 1996–1998)

If you own a 1996-1998 Corolla, the pinout changes to 2 round 28-pin connectors. Here are the critical differences: Probe pin A7 (VTA) – if stuck at

Reference: ECU Pinout for Specific Models

The table above fits most 1992–1995 Corolla AE101 (4AFE). Variations exist:

Water ingress into the kick panel ECU – Leaky windshields or sunroof drains soak the ECU and corrode pins. Check the bottom row of pins (A16–A22) for green crust.

Power and Ground: