Hopefully this answers your questions…
Quote from admin on November 27, 2011
When you are calculating from other PIDs, you don’t need to worry about bytes in the response as they are already converted to a numeric value by the time you put in [0c] (etc) into the equation
If your PID asks the ECU for a response then your byte fields will be put into variables ‘A’ ‘B’ (etc).
So
For a plain old extended PID you may have:
Name: Cylinder 1 Misfire history
PID: 221201
Equation: (A*256)+B
If you were to use that PID in another equation, you may have:
Name: A new PID
PID: (leave blank)
Equation: [221201] + [0c]
Or you can try the best of both:
Name: A pid that makes a request and uses another PID
PID: 22199E
Equation: (A * 0.0195) + [0c]
