Can Bus Network Troubleshooting; Table 5-1 - Status Led Indications; Table 5-2 - Led Indications Recommended Action - Garmin G3X Touch Maintenance Manual

5. Look in the vicinity of the affected LRU for any heavy objects that may not be securely fastened to
the structure, inducing vibration in the ADAHRS.
6. Look for evidence of water or fluid contamination in the area around the affected LRU.
7. Disconnect the affected LRU's connector(s) and check for bent pins.
8. Inspect the wire harness clamp on the rear of the connector to verify that it is not too tight and
smashing/shorting the wires. If the wire clamp is installed upside down, it has sharp edges that can
cut into the wires. Verify the presence of protective wire wrap between the wires and the clamp.
If the condition is not resolved by following the preceding instructions, use data in this section before
contacting Garmin Product Support for additional assistance. A Garmin Field Service Engineer may ask the
technician to download the fault logs via an SD card and email the logs back to Garmin to help determine the
root cause.

5.2 CAN Bus Network Troubleshooting

If communication problems between LRUs are suspected, the CAN bus wiring and arrangement of devices
on the network should be examined.
1. Review the status LED of devices on the CAN bus. The GAD 29B, GEA 24, GSU 25D, GAD 27 and
GSA 28 (if GFC 500 is installed) have an LED on their outer cases that indicates the LRU's current
status. The status indications are shown in Table 5-1:
LED Indication
No light
Steady Green
Flashing Green
Red
Alternating Green/Red
2. Use the guidance in Table 5-2 to troubleshoot LED indications.
LED Indication
No light No power
Steady Green ON, but not
communicating via the
CAN Bus
Flashing Green ON, and communicating
via CAN Bus
Red Hardware Fault
Alternating CAN Bus network error,
Green/Red two similar devices are
configured with the
same unit ID
Maintenance Manual
G3X Touch EFIS Part 23 AML STC
Table 5-1 – Status LED Indications
Table 5-2 – LED Indications Recommended Action
Description
Verify the circuit breaker, power and ground wiring
between the circuit breaker and the affected unit.
Replace the unit if power is available to the unit.
Contact Garmin Product Support before replacing unit to
determine all troubleshooting options have been completed.
Inspect and verify the CAN Bus wiring between the G3X
Touch and the unit
None.
Contact Garmin Product Support (unit may need to be
replaced)
verify the Unit ID strapping on the G3X units. Reference
the G3X Touch EFIS Part 23 AML STC Installation
Manual (190-02472-01) wiring diagrams for strapping
details
Page 32
Description
No power
ON, but not communicating via the CAN Bus
ON, and communicating via CAN Bus
Hardware Fault
CAN Bus network error, two similar devices are
configured with the same unit ID
Recommended Action
190-02472-02
Revision 2