Table 7-1, Itt Indication Test Points - Garmin G1000 Nxi System Maintenance Manual

If the right engine gauge needs to be tested, perform the following:
1. Disconnect all thermocouple wires except for the Alumel-Green #10 and Chromel-White
#8 leads from the right 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 right 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 2 unit replaces the previously installed analog ITT
indicator. Remove GEA 2 unit from its rack to conduct the continuity test from
the terminal block to the GEA 2 unit ITT input pins.
b. If the ITT Wire Harness Continuity Check passes, replace GEA 2.
5. If the test input shows a correct ITT reading within the Indication tolerance in Table 7-1,
troubleshoot the right 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).
If the ITT Tester is not temperature compensated or if using the DC Signal
method, use the chart shown in Figure 7-4 to convert the ambient
temperature to millivolts and subtract from the DC Signal value in Table 7-1.
Test Point (°C)
G1000 NXi System Maintenance Manual
King Air 300 Series
190-00716-N1
NOTE
DC Signal
(mV, subtract
temp offset)
200 8.137
400 16.395
600 24.902
800 33.277
1000 41.269
1200 48.828

Table 7-1, ITT Indication Test Points

Indication (°C)
200 ± 17
400 ± 17
600 ± 12
800 ± 7
1000 ± 12
1200 ± 17
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