Technical data
9
  9. Battery change
CM 8.2: First you should put CM 8.2 into the “Powerdown Mode” (see 
chapter 5 Settings) Open battery cap with a coin (unscrew to the left). 
Insert battery type CR2032 (please use battery with smooth minus-pole) 
with plus-pole facing up. Close battery cap, being sure not to over tigh-
ten. After inserting the battery the display will show normal mode.
(Speed-)Transmitter: Open battery cap at the top of the transmitter 
with a coin (unscrew to the left),  remove old battery and insert new 12 
V battery, type 23A (with pluspole facing up). Close battery cap, being 
sure not to over tighten.
(Battery change in the optional cadence transmitter works in the same 
way.)
Please do not throw away battery in your normal garbage.
  10. Trouble shooting
Faulty or no display
-  check  to  see  if  battery  is  installed  properly  or  replace  battery 
(Attention: removing battery will clear all settings and values)
-  press AC-button on the rear of the computer
Actual Speed not displayed
-  transmitter hasn`t been initialized (see chapter 5)
-  check to see if wheel-sensor is mounted properly    
-  check  the  position  of  the  spoke  magnet  (max.  3  mm  distance  to 
wheel-sensor)
-  make sure CM 8.2 is mounted in bracket correctly
-  check wheel circumference 
-  start transmitter search (press left button for 3 seconds)
Speed to high or to low
-  check wheel circumference    
-  check to see if you are using miles or kilometers  
Transmitters cannot be initialized 
(initialization is very slow or “error” displayed)
-  Tranmitter battery is discharged or transmitter is defect
-  Transmitter has already been initialized  for one of the bikes. If you 
still want to  initialize  the  transmitter for  the  current  bike you  must 
initialize the transmitter again for the other bike, but without an active 
transmitter. “Error” will be displayed. Now you can initialize it again 
with the choosen bike.
Automatic search of the transmitter doesn’t start 
by moving the bike.
-  CM 8.2 is not correctly located in the handlebar bracked
-  A transmitter has already been found (CM 8.2 displays SPD 0) e.g. 
if you  switch  bikes. If  you stay in  the transmitting  area of the  first 
transmitter CM 8.2 displays 0. If CM 8.2 is outside the transmitting 
area  it  will  display  “––“.  With  the  next  movement  of  the  bike  the 
transmitter search will start again.
-  transmitter hasn`t been initialized (see chapter 5)
No heart rate displayed or values displayed are incorrect 
or unstable
-  proof whether heart rate is switched on in setting mode
-  Check transmitter belt (battery)
-  Skin too dry or cold
-  Distance between CM 8.2 and transmitter belt is too big (max. 5m)
-  start transmitter search (press left button for 3 seconds)
Cadence is not displayed or value incorrect or unstable
-  Check whether switched on in setting mode
-  Check sensor and magnet for correct installation
-  start transmitter search (press left button for 3 seconds)
CM 8.2 is making noise
-  its normal because of the automatic movement sensor
PC Recording doesn’t starts
-  storage  is  full,  you  have  to  delete  recorded  tours  (with  HACtronic 
program or the reset function in settings of CM 8.2 see chapter 5; 
Attention: the other values will be deleted also)










