Distributor-based but highly integrated, migrating toward Manifold Absolute Pressure (MAP) sensors for load calculation instead of restrictive air flow meters.
Most 3S-FE ECUs use three multi-pin connectors. I’ll label them Connector A, B, and C for clarity. Pin counts and arrangement differ by ECU case; use this as a mapping reference—confirm with a service manual. 3s-fe ecu pinout pdf
The primary sensor the 3S-FE uses to calculate air mass (since most didn't use an AFM). THW & THA: Distributor-based but highly integrated