TM 1-1520-240-10
2-3-11
Table 2-3-1. T55-GA-714A DECU BIT Fault Code List/Matrix
The DECU fault code matrix will be consulted when anything other than 88 is displayed on the DECU Hex display during
the DECU Pre-Start, Start, or Shutdown BIT checks. The matrix lists DECU fault codes, type of fault, aircraft operational
effect, pilot actions require, and overall mission impact.
Abort mission is defined as: perform a normal engine shutdown and make appropriate entries on the DA Form
2408-13-1.
Continue mission is defined as: the crew may complete the present day’s mission but maintenance troubleshooting
actions are required prior to the next mission.
DECU Fault
Code(s)
Fault
Operational Effect
Pilot Action
Mission Impact
10
DECU internal hard fault.
FADEC light
Aircraft won’t start in Primary
N/A
Abort Mission
11
DECU internal hard fault.
FADEC light
Aircraft won’t start in Primary
N/A
Abort Mission
12
DECU internal soft fault.
N/A
Make an entry on
the DA Form
2408-13-1 even if
fault code clears.
Continue Mission
13
DECU internal soft fault.
N/A
Make an entry on
the DA Form
2408-13-1 even if
fault code clears.
Continue Mission
14
DECU internal soft fault.
N/A
N/A
Continue Mission
15
DECU internal soft fault.
N/A
N/A
Continue Mission
17
DECU internal soft fault.
N/A
Make an entry on
the DA Form
2408-13-1 even if
fault code clears.
Continue Mission
18
DECU internal soft fault.
Without FADEC light
N/A
Continue Mission
18
DECU hard fault.
With FADEC light
N/A
Abort Mission
1B
DECU internal soft fault.
N/A
Make an entry on
the DA Form
2408-13-1 even if
fault code clears.
Continue Mission
1C
DECU internal soft fault.
Without FADEC light
N/A
Continue Mission
1C
DECU hard fault.
With FADEC light
N/A
Abort Mission
1E
DECU internal hard fault.
With FADEC light
Unable to start in Primary
N/A
Abort Mission
1F
DECU internal hard fault.
FADEC light
N/A
Abort Mission
A1
DECU TQ soft fault.
N/A
Select PTIT
Check TQ AC/
DC CBs
Make an entry on
the DA Form
2408-13-1 even if
fault code clears.
Continue Mission
