Garmin G1000 Nxi System Maintenance Manual page 297

GEA Engine Indication Checks
Perform engine indicating systems checks for the left and right engine indications in the
following Sections. To prepare the aircraft for the tests, perform the following:
1. Turn off the G1000 system and remove external power from the aircraft.
2. Open engine cowlings on the left and/or right engines to access firewall connectors and
the ITT thermocouple junction block as needed.
ITT Functional Check
Required test equipment:
Calibrated DC Power Source
If the left engine gauge needs tested, perform the following:
1. Disconnect all thermocouple wires except for the Alumel-Green #10 and Chromel-White
#8 leads from the left hand engine thermocouple junction block mounted to the gas
generator case.
2. Connect the DC Power Source or ITT Tester across the Alumel-Green #10 (-) and
Chromel-White #8 (+) leads of the thermocouple junction block. Make sure the polarity of
the Alumel and Chromel leads are strictly observed when making connections.
3. Apply external power to aircraft and start the G1000 system in normal mode.
4. If the test input shows an incorrect ITT gauge reading outside the Indication tolerance in
Table 7-1, perform the following:
a. Troubleshoot the left engine ITT system per Beechcraft King Air 300 Series
Maintenance Manual, Chapter 77, Airframe ITT Wire Harness Continuity Check.
Note for this test, the GEA 1 unit replaces the previously installed analog ITT
indicator. Remove GEA 1 unit from its rack to conduct the continuity test from
the terminal block to the GEA 1 unit ITT input pins.
b. If the ITT Wire Harness Continuity Check passes, replace GEA 1.
5. If the test input shows a correct ITT reading within the Indication tolerance in Table 7-1,
troubleshoot the left engine ITT system per Beechcraft King Air 300 Series Maintenance
Manual, Chapter 77, using the following checks:
a. ITT Thermocouple Loop Resistance Check
b. ITT Thermocouple Insulation Resistance Check
6. After correcting the condition causing the incorrect ITT reading, turn off the G1000
system and remove external power from aircraft.
7. Reconnect all thermocouple wires to the junction blocks and torque nuts per Beechcraft
King Air 300 Series Maintenance Manual, Chapter 77.
8. If no other EIS gauge tests are needed, reinstall the engine cowling(s).
G1000 NXi System Maintenance Manual
King Air 300 Series
190-00716-N1
Test Equipment
or ITT Tester
Make/Requirement
0-100 mVDC
or 200C-1200C
Page 284
Revision 1