Appendix D
© 2018 Avco Corporation. All Rights Reserved
Page 444
November 2018
TEO-540-C1A Engine Maintenance Manual
Fault ID
184
Fault Group
24
Fault Name
[FAULT: AN10 circuit]
Fault
Description
Primary TIT1 Circuit Fault
Secondary TIT2 Circuit Fault
Fault Lamp
TLO
Root Cause
This fault occurs if the Raw voltage observed on the input is outside the expected window
defined by the calibratable Highest and Lowest Valid Raw voltage values.
This does not distinguish between Open and Short Circuit Faults as any of the following
failures would result in the Raw voltage outside the expected voltage window:
-
Open Circuit - Short to GND
Troubleshooting Steps
1.
Run the engine in accordance with the engine and aircraft maintenance manuals. Is the fault active? * If yes,
go to step 3. If no, go to step 2.
2.
Using the FST, download active and service fault logs, then clear fault logs and monitor engine operation for
the fault to repeat.
3.
Inspect the sensor, sensor connector and lead. If any are damaged, replace the sensor i
per the “Sensor
Replacement Procedure” in Chapter 72-70
. If there is no damage, go to step 4.
4.
Inspect engine harness for visible signs of damage. If damage is found, contact Lycoming Engines. If no
damage is found, go to step 5.
5.
Swap the sensor from the channel giving the fault with another sensor in a different position and run the
engine. Did the fault move with the sensor? If yes, replace the sensor
per the “Sensor Replacement
Procedure” in Chapter 72-70
. If no, complete a continuity test of the harness from the harness sensor
connector to the ECU connector using the engine system schematic. If the continuity check fails, isolate to
affected harness by disconnecting the firewall connection, then contact Lycoming Engines. If the continuity
checks good, replace the ECU.
*NOTE: The steps listed above are for troubleshooting a single fault event. If there are faults on multiple
thermocouples, check to see if there are any active faults for ECU ACJ offset or internal power supply. If
there are any other active faults, as those just mentioned, proceed to the troubleshooting of those faults.
Fault ID
185
Fault Group
24
Fault Name
[FAULT: AN16 circuit]
Fault
Description
Primary MAT (Manifold Air
Temperature) Circuit Fault
Secondary MAT Circuit Fault
Fault Lamp
TLO
Root Cause
This fault occurs if the Raw voltage observed on the input is outside the expected window
defined by the calibratable Highest and Lowest Valid Raw voltage values.
This does not distinguish between Open and Short Circuit Faults as any of the following
failures would result in the Raw voltage outside the expected voltage window:
-
Open Circuit
-
Short to VPwr
-
Short to 5V
-
Short to GND
Troubleshooting Steps
1.
Run the engine in accordance with the engine and aircraft maintenance manuals. Is the fault active? If yes,
go to step 3. If no, go to step 2.
2.
Using the FST, download active and service fault logs, then clear fault logs and monitor engine operation for
the fault to repeat.
3.
Inspect the sensor, sensor connector and lead. If any are damaged, replace the sensor
per the “Sensor
Replacement Procedure” in Chapter 72-70
. If there is no damage, go to step 4.
4.
Inspect engine harness for visible signs of damage. If damage is found, contact Lycoming Engines. If no
damage is found, go to step 5.
5.
Swap the sensor from the channel giving the fault with another sensor in a different position and run the
engine. Did the fault move with the sensor? If yes, replace the sensor
per the “Sensor Replacement
Procedure” in Chapter 72-70
. If no, complete a continuity test of the harness from the harness sensor
connector to the ECU connector using the engine system schematic. If the continuity check fails, isolate to
affected harness by disconnecting the firewall connection, then contact Lycoming Engines. If the continuity
checks good, replace the ECU.
