Supercharged111
Truly Awesome
- Joined
- Aug 20, 2015
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Could be the cluster, the PCM supplies both RPM and speed to the cluster. That said, the speedo output is separate from what it calculates actual vehicle speed to be from VSS input. So with that said, if your cluster is shot but it's consistent it can be fixed with a reflash. . . at least at one speed. If its wrongness trends differently at different speeds you're still screwed. With EFILive, you can opt for whether or not you want trans shift speeds to change with the speedo updates.