| 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 |
To read codes: Jump pin A20 (TE1) to pin A22 (E1) with a paperclip. Turn ignition ON (do not start). Count flashes on check engine light.
Important Note: While the engine is the same, pinouts vary slightly between chassis (e.g., Corolla vs. Celica) and model years (pre-1992 vs. post-1992 OBD-II transition). This guide covers the most common 1990-1995 Toyota Corolla (E90/E100) 4A-FE pinout. Always verify with a multimeter before cutting wires. toyota 4afe ecu pinout
Over 25+ years, the original Toyota wiring suffers from:
For tuners – the 4AFE ECU is not programmable. However, the pinout allows piggyback installation: | Code | Fault | Related Pins |
The Toyota 4A-FE is a 1.6-liter, inline-4 cylinder engine produced from 1988 to the early 2000s. It was the fuel-injected successor to the carbureted 4A-F and became a staple in many global Toyota models, including the Corolla (E90, E100, E110), Geo Prizm, Celica (T18), Carina E, and Corona.
Unlike the sportier 4A-GE, the 4A-FE was designed for fuel efficiency and reliability. It utilizes a distributor-based ignition (with an integrated cam angle sensor) and a manifold absolute pressure (MAP) sensor for load detection, rather than an airflow meter. Important Note: While the engine is the same,
Understanding the ECU pinout is the first step in troubleshooting no-start conditions, sensor failures, or wiring harness damage.