TM 1-1510-262-10
b. Flight Control Computer/Autopilot Mode Annunciation. Flight control computer/autopilot operating modes
are annunciated on the light director mode selector and on each Primary Flight Display (PFD). The light director
command bars, on the coupled side s PFD, relect the guidance command. The navigation sensor used for the
selected modes is chosen with the center Multi-Function Display Control Panel (MFDCP) and annunciated on the
PFD and MFD.
c. Autopilot Self-Disconnection Fault Messages. The pilot can investigate the cause of an in-light autopilot
disconnection by depressing the SBY button on the light director mode selector for more than 5 seconds. The
altitude preselector display will be disconnected from the digital air data computer and connected to the autopilot.
A numerical fault code will appear on the altitude preselector display. Table 3-1 provides an explanation of system
error codes. Subsequent pushes on the SBY button on the light director mode selector will yield additional fault
codes or dashes, which indicate the end of the error code log. When the dashes appear in the display, the altitude
preselector display will again be reconnected to the digital air data computer. Fault messages are displayed as a
letter code followed by a three-digit number. Ignore the last digit of the number, which will be a zero. If the autopilot
was disconnected as a result of the fault, depressing the AP DISC button on the control wheel will allow the autopilot
to be re-engaged, provided the failure no longer exists.
Table 3-1.
Digital Flight Control System Error Codes
FZ-450 Error Codes
Err 00 Processor Reset/Lost Processor
Err 35 Trim Test Fail
01 +15 Volt DC Fail
36 Lateral Accelerometer Fail
02 -15 Volt DC Fail
50 Aircraft ID Fail
03 -5 Volt DC Fail
51 Abbreviated Trim Test Fail
04 +10 Volt DC Fail
52 DG Fail
05 LVC Monitor Fail
53 Hardware Fail
06 Sawtooth Monitor Fail
54 VG No. 1 Fail
55 VG No. 2 Fail
07 26 VAC Reference Fail
08 Watchdog Monitor Fail
56 Pitch Current Monitor Fail
57 Roll Current Monitor Fail
09 Interrupt Register Fail
10 A/D End-Around Fail
58
11 EEPROM Full
59 Vertical Gyro Comparison Fail
12 PROM Checksum Fail0
60 Pitch Servo Loop Fail
13 RAM Read/Write Fail
61 Roll Servo Loop Fail
14 CPU Register Fail
63 Servo Fail
15 CPU Instruction Set Fail
64 Excessive Lateral Acceleration
16 RAM Continuous Fail
65 Pitch Trim Fail
17 Essential RAM Checksum Fail
66 Excessive Vertical Acceleration
18 Continuous A/D and D/A Test Fail
67 Excessive Roll Rate
19 Continuous PROM Test Fail
68 Wrong Trim Polarity
20 Ticket Fail
69 RG Valid Fail
21 CPU Fail
70 26 VAC Cross-side reference Fail
30 Pitch Magnitude Rate Limiter Fail
71 AP Disconnect PB Fail
31 Roll Magnitude Rate Limiter Fail
72 Turn Knob Detent Fail
33 Roll Torque Fail
73 Manual Trim Input Fail
34 Pitch Torque Fail
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