Daihatsu L9 Ecu Pinout Fix | Wiring Diagram

L9 ECUs come in different generations. The "Old Type" (often 2 plugs) and "New Type" (often 3 plugs or different pin counts) have different pin assignments. The guide below focuses on the most common configuration found in the Mira/Cuore L9 series.

660cc 3-cylinder, dual-overhead-cam (DOHC) turbocharged engine. wiring diagram daihatsu l9 ecu pinout

| Pin No. | Signal/Circuit | Function Description | | :--- | :--- | :--- | | | Battery Backup | Provides constant 12V power to maintain ECU memory (e.g., learned fuel trims). | | A2 | Main Relay Control | ECU output that turns on the main relay, powering the injectors and sensors. | | A3 | Ground (Power) | High‑current ground for the injector and ignition drivers. | | A4 | Ignition Switch (IG) | Receives 12V when ignition is ON. This is the ECU's main power supply. | | B1 | Check Connector (T) | Diagnostic terminal (often shorted to ground to flash trouble codes). | | B2 | Engine RPM (IGf) | Ignition feedback signal from the igniter to the ECU for tachometer operation. | | B3 | Vehicle Speed Sensor (VSS) | Input from the speedometer or transmission sending unit. | | B4 | Coolant Temperature Sensor | Analog input (thermistor) used for cold‑start enrichment and fuel calculation. | | C1 | Throttle Position Sensor (TPS) | Analog input that indicates throttle plate angle (idle to full throttle). | | C2 | Injector 1 (#1) | ECU output that switches ground to open the No. 1 fuel injector. | | C3 | Injector 2 (#2) | ECU output that switches ground to open the No. 2 fuel injector (3‑cylinder). | | C4 | Injector 3 (#3) | ECU output that switches ground to open the No. 3 fuel injector (3‑cylinder). | | C5 | Oxygen Sensor | Heated oxygen sensor (HO2S) input used for closed‑loop fuel control. | L9 ECUs come in different generations

: For models requiring custom OBD-II port installation, the following pin connections are standard: Socket B, Pin 14 : Pink wire, connects to OBD-II Pin 1. Socket B, Pin 11 : Yellow wire, connects to OBD-II Pin 9. ECU Pin 16 : Connects to direct battery power for constant current. General Signal and Color Coding (L9 Series) | | A2 | Main Relay Control |