The 17C61 ECU has a 64-pin configuration, with pins divided into several categories:
Precision control pins for fuel injectors, EGR valves, and turbocharger actuators. Programming & Repair Tools 17c61 ecu pinout
The 17C61 ECU uses : A, B, and C. They are keyed differently to prevent incorrect plugging. The 17C61 ECU has a 64-pin configuration, with