System Maintenance Manual

Page 5-22 G1000/GFC700 System Maintenance Manual – C90A/C90GT/C90GTi King Air
Revision F 190-00682-01
Invalid Data Field
Associated
LRU(s)
Solution
ATTITUDE FAIL
GRS 77
• Ensure that a cell phone or a device using cell phone
technology is not turned on (even in a monitoring
state) in the cabin.
• Cycle GRS 77 power to restart initialization.
• Ensure GRS 77 connecter is secure and proper wire
harness strain relief is provided.
• Ensure the GRS 77 is fastened down tightly in its
mounting rack and that the mounting rack is not
loose (CAUTION - do not loosen the mounting rack
hardware to the airframe shelf or the aircraft will need
to be re-leveled and the PITCH/ROLL OFFSET
procedure performed).
• Ensure GPS has acquired at least four satellites, has
a 3D navigation solution, and a DOP of less than 5.0.
This is particularly important for an ATTITUDE FAIL
that appears during ground operation only.
• Perform an Engine Run-Up Test to check if engine
vibration is causing the GRS 77 to go offline.
• Load configuration files to the PFD, MFD, GIA1, and
GIA2.
• Calibrate the GRS 77 (Pitch/Roll Offset and
Magnetometer Calibration).
• Replace GRS 77.
9 If problem persists replace GRS 77 configuration
module.
9 Contact Garmin Aviation Product Support if
condition continues after replacing the GRS 77
and config module for additional assistance.