: Pins generally handle sequential fuel injection signals for cylinders 1 through 4. : Dedicated pins exist for the Mass Air Flow Meter
Regarding the ECU pinout, the 2NZ-FE engine control unit (ECU) is a computer that controls the engine's performance, fuel injection, ignition timing, and emissions. The ECU pinout refers to the configuration of the electrical connections on the ECU. 2nz Fe Ecu Pinout Pdf 186
Expect 0 to 3 Volts with the ignition ON and ECM connector C disconnected. Pin A3 (Ignition Coil Feedback - IGF): : Pins generally handle sequential fuel injection signals