AiM MyChron3 XG Log - Manual (Page 30)

Case 1: if you turned off the engine and stopped the vehicle
without switching off the gauge, the red led AL 1 starts
blinking, informing the driver that the gauge is calculating the
threshold values.
Case 2: otherwise, if you switched off the gauge together with
the engine, the gear calculation procedure starts once you re-
switch on the gauge (the red led AL 1 blinks).
Once the red led AL 1 stops blinking, the gear calculation
procedure is completed: now you will be able to see the gear
value inside the gauge’s gear display.
If the gear values displayed do not correspond to the engaged
gears, please repeat the gear calibration procedure.
It is reminded that the threshold values are saved in the
gauge’s internal memory and the user will not have to
calculate them each time the gauge is switched on.
The algorithm is able to detect the engaged gear as it
calculates the engine’s RPM vs. speed ratio. If the speed is
acquired from a non-driving wheel, the algorithm may return
incorrect gear values.
The RPM vs. speed ratio is directly proportional to the
transmission/gearbox ratio and to the wheel circumference: if
one of them (or both) is changed, the gear calibration
procedure may have to be repeated.
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