Lycoming TEO-540-C1A Maintenance Manual page 501

TEO-540-C1A Engine Maintenance Manual
Fault ID 272
Primary: Venturi Pressure External
Fault
Description
Secondary: -reserved-
This fault implies that the 5V sensor supply that is connected to the sensor is deemed
INVALID.
1: The 5V supply may be INVALID due to a circuit fault or a slew-rate fault on the 5V
supply. For details of the 5V Supply faults refer to Fault Ids 160-162, 196-198 and 264-
Root Cause 266.
2: Multiple sensors may be connected to the same 5V supply so if it becomes INVALID
then all the sensors that are connected to it would set corresponding External (sensor
supply) faults. Refer to the system schematic to identify the sensors that may be
connected to a 5V supply.
1. Is there an active fault(s) that correspond to the fault numbers listed in the Root Cause box, items 1 and
2? If yes, go to troubleshooting procedure for the active fault(s). If no, go to step 2.
2. With the ECU powered on, use a multi-meter to measure the voltage at the sensor connector A039-P pin
B (5V supply) and pin A (GND). Is 5V present on pin B? If yes, replace the sensor. If no, go to step 3.
3. Inspect engine harness for visible signs of damage. If damage is found, contact Lycoming Engines. If
no damage is found, go to step 4.
4. Complete a continuity test of the harness from the harness sensor connector A039-P 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.
Fault ID 273
Primary: Deck Pressure External
Fault
Description Secondary: Deck Pressure External
This fault implies that the 5V sensor supply that is connected to the sensor is deemed
INVALID.
1: The 5V supply may be INVALID due to a circuit fault or a slew-rate fault on the 5V
supply. For details of the 5V Supply faults refer to Fault Ids 160-162, 196-198 and 264-
Root Cause 266.
2: Multiple sensors may be connected to the same 5V supply so if it becomes INVALID
then all the sensors that are connected to it would set corresponding External (sensor
supply) faults. Refer to the system schematic to identify the sensors that may be
connected to a 5V supply.
1. Is there an active fault(s) that correspond to the fault numbers listed in the Root Cause box, items 1 and
2? If yes, go to troubleshooting procedure for the active fault(s). If no, go to step 2.
2. With the ECU powered on, use a multi-meter to measure the voltage at the sensor connector A045-P
(Primary) or A036 (Secondary) pin C (5V supply) and pin A (GND). Is 5V present on pin C? If yes,
replace the sensor. If no, go to step 3.
3. Inspect engine harness for visible signs of damage. If damage is found, contact Lycoming Engines. If
no damage is found, go to step 4.
4. Complete a continuity test of the harness from the harness sensor connector A045-P or A036-P 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.
© 2018 Avco Corporation. All Rights Reserved
November 2018
Fault Group
(Sensor Supply Fault)
Troubleshooting Steps
Fault Group
(Sensor Supply Fault)
(Sensor Supply Fault)
Troubleshooting Steps
35 Fault Name
Fault Lamp
35 Fault Name
Fault Lamp
[FAULT: venturi pressure external]
TLO
[FAULT: local deck pressure external]
TLO
Appendix D
Page 471