Appendix D
© 2018 Avco Corporation. All Rights Reserved
Page 418
November 2018
TEO-540-C1A Engine Maintenance Manual
Troubleshooting Steps for Faults 80 thru 87 (Cont.)
3.
Using the FST, download active and service fault logs.
4.
Review logs to determine if the same fault has occurred on other cylinders as shown in the chart above.
If yes, go to step 5. If not, go to step 6.
5.
If faults occur per Group 1 or Group 2, complete a continuity check using the engine system schematic
and the table below. If the continuity check is good, replace the ECU. If the continuity check fails,
isolate to affected harness by disconnecting firewall harness, contact Lycoming.
Group 1
ECU
Connector
Pin
Sensor Connector
Pi
n
Connector
Pin
Sensor Connector
Pin
A001-P1
35
A015-P
1
ECU A001-
P1
36
A015-P
2
25
A017-P
1
A017-P
2
26
A019-P
1
Group 2
A001-P2
35
A016-P
1
ECU A001-
P2
36
A016-P
2
25
A018-P
1
A018-P
2
26
A020-P
1
6.
Swap detonation sensor with another cylinder. If fault moves with sensor, replace the sensor. If fault
does not move with sensor, complete a continuity check of harness from harness knock sensor connector
to ECU connector using the engine system schematic. If the continuity check fails, isolate to affected
harness by disconnecting firewall harness, contact Lycoming. If the continuity check passes, replace the
ECU.
NOTE: If all steps are unsuccessful, contact Lycoming.
Fault ID
88
Fault Group
12
Fault Name
[FAULT: cam sensor]
Fault
Description
Cam sensor fault
Fault Lamp
NTO
Root Cause
This fault indicates that a cam synchronization has failed due to an incorrect number of
teeth detection or no teeth detection. This fault also indicates an issue with the cam sensor
and will be cleared if correct teeth detection resumes
Troubleshooting Steps
1.
Run the engine in accordance with the engine and aircraft maintenance manuals. Is the fault active? If
yes, go to step 4. If no, go to step 2.
2.
Using the FST, download active and service fault logs. Go to step 3.
3.
Review logs to determine if a fault was set. If there are no active faults, but fault keeps reoccurring,
then go to step 4.
4.
Inspect cam sensor 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 5.
5.
Swap cam sensor with crank sensor. Is the ECU now giving a crank sensor fault? If yes, replace the
cam sensor. If no, go to step 6.
6.
Complete a continuity test of the harness from the harness cam sensor connector to 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 check is good,
replace the ECU.
