Also, there is some data on the web about the ECU / Cluster communications protocol, but its pretty limited and incomplete the last I looked.
FWIW: there is single wire for data from ECU -> Gauge
USD bikes, the data wire generates the following:
- tach / RPM
- vehicle speed & trip distance
- water & air temperature
- Trouble light (CEL)
- Engine coolant warning lamp
- diagnostic data
- CO (C1/C2) offsets
- maybe other stuff...
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Turn signals L & R, high-beam indicator, oil & fuel level, back-light, Neutral, etc all come from other inputs...
This is from memory so its subject to error... It was to give you an idea. Are you trying to decode the communications from ECU to Gauge??