| Code | Fault | Related Pins | |------|-------|----------------| | 11 | No IGF signal | Pin 13 (IGF) | | 12 | No G signal (distributor) | Pin 11 (G-) | | 13 | No NE signal (cam/crank) | Pin 11 circuit | | 14 | No IGt signal | Pin 12 (IGt) | | 21 | Oxygen sensor fault | Pin B4 (O2), B5 (HT) | | 22 | Coolant temp sensor | Pin 10 (THW) | | 24 | Intake air temp | Pin B7 (ACT) | | 31 | Airflow meter/MAP | Pin 9 (PIM) | | 41 | TPS circuit | Pin 7 (VTA), Pin 8 (VC) | | 51 | Switch condition (A/C, NSS) | Pin A14, B2, B10 |
The Toyota 4A-FE engine uses several ECU configurations depending on the vehicle generation (e.g., AE92, AE101, AE111) and the region (Japan vs. Export). Most commonly, you will find a 26-pin / 16-pin / 22-pin connector setup. 🛠️ Common ECU Pin Functions toyota 4afe ecu pinout
| Symptom | First Pin to Check | Expected Reading | |----------|--------------------|-------------------| | No start, no CEL with key ON | Pin A1 (B+) | 12V | | Fuel pump doesn’t prime | Pin A19 (FC) | 0V for 2 sec, then open | | CEL stays on, no codes | Pin A2 (Main relay) | 12V at relay coil | | Rough idle, surges | Pin A9 (PIM) | 3.5V at idle, steady | | No power above 4000 RPM | Pin A12 (IGt) | Clean square wave to 5V | | Check engine light won’t flash codes | Jump TE1 (A20) to E1 (A22) | Must be solid ground | | Code | Fault | Related Pins |