💡 Always verify the "Type" of your ECU (Type 1 vs. Type 2) before testing. Connecting power to a ground pin can permanently damage the ECM.

| Pin No. | Function | Typical Wire Color | Notes | | :--- | :--- | :--- | :--- | | | Ignition Power (Main) | Black/White | +12V when key is ON | | 3 | Ground (Earth) | Black | Chassis/Signal Ground | | 9 | Check Engine Light | Blue/Red | Grounds the bulb to trigger light | | 22 | Tachometer Signal | White | Output to cluster | | 23 | Vehicle Speed Sensor | Green/White | Input from transmission | | 41 | Crankshaft Position Sensor | White | Critical for spark/fuel | | 42 | Camshaft Position Sensor | Red | Synchronizes injection | | 55 | Data Link Connector (CAN High) | Pink | For OBD2 scanning | | 56 | Data Link Connector (CAN Low) | Blue | For OBD2 scanning |

In this guide, we will provide a detailed breakdown of the YD25 ECU pinout, explain why it is critical for your project, and show you how to access a , accurate pinout diagram.

These models primarily use the 121-pin terminal layout. The connector is a slide-locking type

Always disconnect the negative terminal before unplugging or plugging in the ECU to prevent voltage spikes.

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