VDO M4WL User Manual
Page 44
44
M4 WL
Recalibrating the altitude before starting
Why is it necessary to recalibrate the M4 WL? 
The M4 WL measures the current air pressure and converts 
it into an altitude measurement. The air pressure changes 
daily depending on the weather. This leads to a constantly 
changing current altitude measurement 
HOWEVER: your home start altitude has not changed. 
During recalibration, the currently measured air pressure is 
recalculated on the basis of a reference value – the preset 
start altitude for your home.
Following recalibration, the M4 WL again correctly displays 
the start altitude as the current altitude. 
To calibrate the cycle computer,
press and hold the
ALTI button until the menu opens.
“Altitude SELECT” flashes on the display.
You can now choose whether you want to: 
– set the current altitude to the correct value
– set the current sea level pressure to the correct value
– use the start altitude 1 as the reference value for the 
 recalibration
– use the start altitude 2 as the reference value for the 
 recalibration
Press the
BIKE or ALTI button to scroll to Home Alti 1 or
Home Alti 2 depending on where you are setting off from. 
Press the 
SET button to confirm the desired start altitude.
The M4 WL now stores the preset values and displays the 
start altitude as the current altitude at your present location.