2005-2008 Honda ATV TRX500FA/FGA Fourtrax, Rubicon Factory Service Manual, Page 485Get this manual
HONDAMATIC 6Move the drive mode select switch to D1 or D2DRIVE MODE SELECT SWITCH
7Turn the ignition switch ON while pushing both the UP and DOWN shift switches (ESP shift switches) simultaneously (Do not release the shift switches yet)Wait moment and check that the "N" blinks at the gear position indicator8Immediately release both the UP and DOWN shift switches, then push and release the shift switches in the order of UP, DOWN and UP (Do not hold onto the switch)If the gear position indicator shows the constant display of "N" or the control motor did not cycle, turn the ignition switch OFF and repeat the procedure from step 7