Lycoming TEO-540-C1A Maintenance Manual page 450

Fault ID 91
Fault
Prop-pitch output driver fault
Description
This fault occurs to indicate inability to control the Propeller Pitch actuator as desired due
to a circuit fault. The circuit fault may be internal to the ECU (drive stage) or external to
the ECU (load or harness).
The fault is set under any one of the following conditions:
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Root Cause
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1. Run the engine in accordance with the engine and aircraft maintenance manuals. Is the fault active? If
yes, go to step 2. If no, go to step 3.
2. Are there faults on both primary and secondary channels for the propeller governor? If yes, go to step 5.
If no, go to step 6.
3. Using the FST, download active and service fault logs. Go to step 4.
4. Review logs to determine which fault was set, and if there are more than one fault. If there are no active
faults, but fault(s) keep reoccurring, go to step 5.
5. If faults are found on both channels, inspect harness for damage (eg...burned, broken or frayed wires,
cracked or broken connectors). If damage found, contact Lycoming. If no damage found, replace the
propeller governor.
6. Inspect propeller governor harness connection for any damage (eg...burned, broken or frayed wires,
cracked or broken connectors). Contact Lycoming if harness damage is found. If no damage is found,
go to step 7.
7. Complete a continuity test of the harness from the harness injector connector to ECU connector A001-
P3, and A001-P4, 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
check is good, replace the ECU.
Fault ID 92
Fault
Description
Root Cause
Fault ID 93
Fault
Description
Root Cause
Appendix D
Page 420
Fault Group
The actuator or the drive stage is Open-circuit
The actuator is short-circuited
Low Side Drive (LSD) is shorted to the GND
High Side Drive (HSD) is shorted to the GND
LSD is shorted to the V Supply
HSD is shorted to the V Supply
Troubleshooting Steps
Fault Group
Troubleshooting Steps
Fault Group
Troubleshooting Steps
TEO-540-C1A Engine Maintenance Manual
12 Fault Name
Fault Lamp
12 Fault Name
Fault Lamp
12 Fault Name
Fault Lamp
© 2018 Avco Corporation. All Rights Reserved
[FAULT: prop-pitch output failure]
NTO
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NTO
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NTO
November 2018