Garmin G5 Maintenance Manual page 23

b. Using an ohm meter, verify that the resistance between the CAN HI and CAN LO pins on
the connector is 60 ohms. This will verify that the CAN backbone is properly terminated
at each end (two 120 ohm terminating resistors in parallel).
c. A resistance of 120 ohms indicates that one of the two required CAN terminations is
missing.
d. A resistance of 40 ohms or less indicates that too many terminations are installed.
e. Verify that the CAN HI and CAN LO signals are not swapped, shorted together, or open-
circuited at any LRU connector.
f. Verify that the CAN HI and CAN LO signals are not shorted to ground (this can happen
when shielded wire is installed incorrectly).
NOTE
If a Lightning Protection Module is installed, check for continuity between backshell leads per
Garmin G5 Electronic Flight Instrument Part 23 AML STC Installation Manual, 190-01112-10
section 5.
5) If the problem persists, replace the GMU 11 with a known good unit.
5.1.5 VHF Navigation Information (Installations without a GAD 29/29B Installed)
If the VHF navigation information is removed from the G5 HSI display:
1) On the G5 in configuration mode, select the RS-232 configuration page, verify there is a Green
Check by 'Input Format, Garmin VHF NAV Radio' and 'Output Format, Garmin VHF NAV
Radio'. If there is a Red-X by either of these items, proceed to the next step.
2) Check the RS-232 wiring connected between the G5 and the VHF Navigator using the instructions
in the General section above.
3) Verify the VHF Navigator configuration has not changed from the initial installation. Reference
APPENDIX A .
4) If the problem persists, replace the G5 or VHF Navigator with a known good unit.
5.1.6 VHF Navigation Information (Installations with a GAD 29/29B Installed)
If the VHF navigation information is removed from the G5 HSI display:
1) On the G5 in configuration mode, select the Device Information page, select A429 and verify
there is a Green Check by A429. If there is a Red-X by A429, proceed to the next step.
2) Check the ARINC 429 wiring connected between the G5 and the GAD 29/29B using the
instructions in the General section above.
3) The GAD 29/29B has an LED on the outer case that indicates the LRUs current status. The status
indications are:
Garmin G5 Electronic Flight Instrument Part 23 AML STC Maintenance Manual
Page 15 of 54
190-01112-11
Rev. 7