Lycoming TEO-540-C1A Maintenance Manual page 567

TEO-540-C1A Engine Maintenance Manual
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 the 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 cylinder 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.
© 2018 Avco Corporation. All Rights Reserved
November 2018
Troubleshooting Steps for Faults 552 thru 559 (Cont.)
Appendix D
Page 537