Ahrs Align Message (Pfd) - Garmin GDU 370 Installation Manual

9.3.2 Heading/Pitch/Roll Troubleshooting
The GSU 73 may not be able to provide valid heading/pitch/roll data for the following reasons:
1. The GSU 73 external memory module in the harness (that stores the installation configuration
parameters) is either not present or not wired properly. If this is the case, then the external
installation configuration parameters will not be considered calibrated. If an "AHRS not
Calibrated" message is displayed, the AHRS and/or Magnetometer calibration needs to be
performed, or the GSU 73 configuration module is inoperative.
2. The external installation configuration parameters are not considered calibrated. These
parameters are categorized into 2 sets: AHRS installation, and Magnetic installation. If either
of these is not calibrated, the GSU 73 heading, pitch, and roll may all be flagged as invalid
and an "AHRS not Calibrated" message is displayed. Calibrate the unit to the installation.
3. There is not sufficient or valid sensor information being provided to the GSU 73 for it to
compute valid attitude information. Table 9-1 summarizes the inputs the GSU needs to
provide Attitude and Heading information.
Page 9-6
Revision A
Figure 9-4 – AHRS Align Message (PFD)
G3X Installation Manual –Troubleshooting
190-01115-01