ECU Circuit Schematic Diagrams
Armed with a pencil, some scratch paper, and a jewelers loupe, I traced the wiring between most of the components. From that, I generated a set of schematics for the Aprilia fuel injection computer, or ECU. The scribbled notes were then transcribed into schematic diagrams using Cadsoft Eagle.
Yes, it took a long time.
You should be aware that these circuit diagrams are neither complete, nor guaranteed to be correct. In fact, I should mention that I am a software guy and not a hardware engineer, so you might take my interpretation of the circuitry with a grain of salt. If you spot mistakes or if you just happen to understand this stuff better than me, please let me know and I can fix these diagrams.
So if that is enough disclaimers, the schematics can be found below as '.png' graphics files. For what it is worth, the schematics are designed to be printed at 200 DPI.
- sheet 1 (Ignition Coil Drivers)
- sheet 2 (Ignition Event Detection [IC3/IC4 Generation])
- sheet 3 (Injector Drivers)
- sheet 4 (Map Selection & Test Mode inputs)
- sheet 5 (Side Stand & Clutch Switch inputs)
- sheet 6 (Voltage Monitor)
- sheet 7 (Air temperature/Coolant temperature inputs)
- sheet 8 (Analog Mux. inputs)
- sheet 9 (Tip-over sensor)
- sheet 10 (CO trim pots)
- sheet 11 (Throttle angle sensor)
- sheet 12 (MAP sensor)
- sheet 13 (CPU)
I should put in a plug here for the Cadsoft Eagle schematic capture program. It is a very fine program. Even the freeware version does two-sided auto routing of traces for schematics that fit onto a single sheet. I liked the program so much that I bought the "non-profit" license so that I could generate multi-page schematics.
It will be worth it in the end.
Wright Cyclone in full song.
