TM 1-1510-225-10 3D-74 d.  STA  4  Page.    The  STA  4  page  displays  the KLN 90B’s total operating time and also the number of times the unit has been turned on.  These values are set  to  zero  if  the  KLN  90B’s  nonvolatile  memory  is cleared. 3D-29.  MESSAGES. a.   Message   Page.      The   following   is   a   list   of messages that can appear on the message page. (1)   ACTV     ANNUNCIATOR     FAIL     - This message  appears  when  there  is  a  failure  of  the  KLN 90B ACTV annunciator drive circuitry.  To determine if the approach mode is active, look at the status line of the KLN 90B. (2)   ADJ  NAV  IND  CRS  TO  123°  -  The  pilot should select the suggested course on the EHSI.  This message occurs at the beginning of turn anticipation.   It   also   appears   when   the   difference   between   the EHSI's selected course and the desired track (DTK) is greater than 0.5°. (3)   ADJ  NAV  IND  CRS  - This message may appear in installations where the KLN 90B is interfaced with  EFIS  or  with  a  mechanical  EHSI  through  the  KA 90 adapter.  Appears when the difference between the EHSI’s  selected  course  and  the  KLN  90B’s  selected course is greater than 0.5°. (4)   AIRSPACE    ALERT    -     This     message indicates estimated time to enter special use airspace is  approximately  10  minutes  or  the  distance  is  less than 2 nautical miles. (5)   ALTITUDE FAIL - This message indicates that the altitude input failed.  Altitude related features will be disabled. (6)   APT    ELEVATION    UNKNOWN    -    This message   indicates   that   airport   elevation   for   height above airport alert unknown. (7)   ARINC    429    AIR    DATA    FAIL    -    This message   indicates   that   the   air   data   systems   with ARINC 429 outputs are not being received correctly by the KLN 90B. (8)   ARINC     429     OUTPUT     FAIL - This message   indicates   that   the   KLN   90B   ARINC   429 output  fails  test.    This  affects  EHI  40/50  electronic EHSI and some navigation graphics displays. (9)   ARM ANNUNCIATOR FAIL - This message  displays  when  there  is  a  failure  of  the  KLN 90B  ARM  annunciator  drive circuitry.  To determine if the approach mode is armed, look at the status line of the KLN 90B. (10)ARM  GPS  APPROACH  –  If  the  approach arm   mode   has   been   disarmed,   the   KLN   90B   will prompt arming the approach mode when the aircraft is three nautical miles from the FAF. (11)BAD SATELLITE GEOMETRY AND RAIM NOT  AVAILABLE  –  Appears  only  if  in  the  approach active  mode,  RAIM  is  not  available,  and  the  satellite geometry    has    further    degraded    to    cause    more uncertainty of the aircraft position. (12)BAD  SATELLITE  GEOMETRY  SEE  EPE ON  STA  2  PAGE  –  RAIM  is  not  available.  Possible position  error  is  greater  than  allowed  for  IFR  flight.   Crosscheck   the   position   of   the   aircraft   with   other means of navigation. (13)BATTERY   LOW:   SERVICE   REQUIRED TO   PREVENT   LOSS   OF   USER   DATA   –  Internal battery is low and needs replacement. (14)CHECK ACTV ANNUNCIATOR – A failure between    the    KLN    90B    and    the    annunciator.    To determine if the approach  -mode is active, look at the status line of the KLN 90B. (15)CHECK  ARM  ANNUNCIATOR  –  A  failure between    the    KLN    90B    and    the    annunciator.    To determine if the approach mode is armed, look at the status line of the KLN 90B. (16)CHECK  MSG  ANNUNCIATOR  – A failure between    the    KLN    90B    and    the    annunciator.    To determine  if  message  alerting  is  being  given,  check the display of the KLN 90B. (17)CHECK  WPT  ANNUNCIATOR  –  A  failure between    the    KLN    90B    and    the    annunciator.    To determine if waypoint alerting is being given, check the display of the KLN 90B. (18)DATABASE CHECKSUM ERR – Database  fails  internal  test.    Most  likely  cause  is  a failed database cartridge. (19)DATABASE   OUT   OF   DATE   ALL   DATA MUST BE CONFIRMED BEFORE USE – Database is out of date. (20)EEPROM  FAILURE:  1C  ___  EXTERNAL D-BAR INVALID  –  The  blanks  contain  the  designator of  a  specific  failed  component.    Record  the  data.    Do not use it and external EHSI.  The rest of the KLN 90B is  still  usable  including  the  internal  CDI.    The  page displays may not be centered on the screen.