Maintenance Manual 190-02472-02G3X Touch EFIS Part 23 AML STC Revision 2Page 325. Look in the vicinity of the affected LRU for any heavy objects that may not be securely fastened tothe 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 andsmashing/shorting the wires. If the wire clamp is installed upside down, it has sharp edges that cancut 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 beforecontacting Garmin Product Support for additional assistance. A Garmin Field Service Engineer may ask thetechnician to download the fault logs via an SD card and email the logs back to Garmin to help determine theroot cause.5.2 CAN Bus Network TroubleshootingIf communication problems between LRUs are suspected, the CAN bus wiring and arrangement of deviceson 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 andGSA 28 (if GFC 500 is installed) have an LED on their outer cases that indicates the LRU’s currentstatus. The status indications are shown in Table 5-1:Table 5-1 – Status LED Indications2. Use the guidance in Table 5-2 to troubleshoot LED indications.Table 5-2 – LED Indications Recommended ActionLED Indication DescriptionNo light No powerSteady Green ON, but not communicating via the CAN BusFlashing Green ON, and communicating via CAN BusRed Hardware FaultAlternating Green/Red CAN Bus network error, two similar devices areconfigured with the same unit IDLED Indication Description Recommended ActionNo light No power Verify the circuit breaker, power and ground wiringbetween the circuit breaker and the affected unit.Replace the unit if power is available to the unit.Contact Garmin Product Support before replacing unit todetermine all troubleshooting options have been completed.Steady Green ON, but notcommunicating via theCAN BusInspect and verify the CAN Bus wiring between the G3XTouch and the unitFlashing Green ON, and communicatingvia CAN BusNone.Red Hardware Fault Contact Garmin Product Support (unit may need to bereplaced)AlternatingGreen/RedCAN Bus network error,two similar devices areconfigured with thesame unit IDverify the Unit ID strapping on the G3X units. Referencethe G3X Touch EFIS Part 23 AML STC InstallationManual (190-02472-01) wiring diagrams for strappingdetails
