TM 1-1510-218-10 3C-80 Table 3C-16.  CDU Annunciation Line Priorities ANNUNCIATIONS ident no gps appr sincgars cue inux battery m4 warn no appr raim speed wpt passed m4 reply no keys zero status pca intercept locked safe keys exiting hold crs reversal version xtk alert hold active baroset no appr vnav bank limit intr active approach discontinuity nav source crp active need key verify proc nav error rfl active wrong key enter utc gps fg8 active load fail timer 1 compare gps rtk active data expired timer 2 no RAIM cir active update magvr timer 3 inux key alert XXXX:XX  ¹ XXXX:XX represents the UTC time (e.g., 0810:40) Table 3C-17.  Additional Alerts   TYPE OF ALERT INITIATING CONDITION Waypoint Within waypoint alert prior to waypoint sequence when in EN ROUTE and OCEANIC  sensitivity  modes.    Ten  seconds  prior  to  waypoint  sequence when in TERMINAL and APPROACH sensitivity modes. Terminal FMS in Terminal Mode. Approach FMS in Transition or Approach Mode. RAIM Alert GPS RAIM function detects error (RAIM Warn). Parallel Track Parallel offset has been applied to the active flight plan. CDU MSG Alert Light The   MSG   Alert   column   in   this   table   lists   which   annunciations   are accompanied by a message alert. No     INPUT     (with     a     blank screen) A  bus  terminal  has  taken  control  of  the  MIL-STD -1553  bus,  but  is  not responding  as  a  bus  controller.    Activate  the  bus-split  switch  to  split operations and isolate the faulty device on the 1553 bus. Or CDU has experienced   a  catastrophic  failure  of  the  CDU  chip  or  a  flash memory  fault  and  should  not  be  used  for  navigation  because  navigation data   may   be   corrupted   and   extremely   unreliable.      Switch   to   backup navigation means immediately. NOTE Resetting  the  CDU  power  may  restore  full  operation  if  the failure   was   caused   by   the   CDU’s   misreading   its   terminal address   during   cyclic   power   fluctuations.      If   this   occurs, cross-check  all  navigation  data  until  you  are  ensured  that the primary FMS-800 system is operating properly.