The Mitsubishi 4M51 engine is a diesel engine used in various applications, including trucks and buses. The ECU (Engine Control Unit) pinout is a crucial piece of information for tuning, troubleshooting, and modifying the engine.

| Pin # | Signal Name | Description | | --- | --- | --- | | 16 | Vehicle Speed Sensor (VSS) | Vehicle Speed Sensor | | 17 | Transmission Control Switch | Transmission Control Switch | | 18 | A/C Compressor Clutch Relay | A/C Compressor Clutch Relay | | 19 | Fan Relay | Cooling Fan Relay | | 20 | Fuel Heater Control | Fuel Heater Control | | 21 | Intake Manifold Pressure Sensor (MAP) | Intake Manifold Pressure Sensor | | 22 | Exhaust Gas Pressure Sensor (EGPS) | Exhaust Gas Pressure Sensor | | 23 | DPF Differential Pressure Sensor | DPF Differential Pressure Sensor | | 24 | Lambda Sensor | Lambda Sensor ( Oxygen Sensor) |

A very specific request!

Keep in mind that this pinout might not be accurate for your specific ECU or application. It's essential to verify the pinout with a reliable source, such as a repair manual or a dealership, to avoid any damage or incorrect configurations.

After researching, I found a possible pinout for the Mitsubishi 4M51 ECU: