(a) On the P5 panel push the applicable MACH AIRSPEED WARNING TEST switch.

EFFECTIVITY SIL ALL  34-16 TASK 801 
D633A103-SIL BOEING PROPRIETARY -Copyright # Unpublished Work -See title page for details  Page 201 Jun 10/2006 

1) If the Mach airspeed warning does sound, then you corrected the fault.
2) If the Mach airspeed warning does not sound, then continue.
(2)  
Do
this
task:
ADIRS
BITE
Procedure,
34-21
TASK
801.

(a)  On the P5 panel push the applicable MACH AIRSPEED WARNING TEST switch. 1) If the Mach airspeed warning does sound, then you corrected the fault. 2) If the Mach airspeed warning does not sound, then continue.

(3)  
For the applicable Mach Airspeed Warning System, do this check of the wiring:

(a)  
Remove the Flight Recorder/Mach Airspeed Warning Test Module. To remove it, do this task: Flight Recorder/Mach Airspeed Warning Test Module Removal, AMM TASK 31-31-12-000-801.

(b)  
Remove the Aural Warning Module, M315. To remove it, do this task: Aural Warning Module Removal, AMM TASK 31-51-04-000-801.

(c)  
Do a check for an open circuit between these pins:

MAS AURAL WARN CONNECTOR CONNECTOR

MAS 1 D483  D1172
pin16 -------------------pin2

MAS 2 D483  D940
pin6 -------------------pin10

(d)  
Repair the wiring.

(e)  
Re-install the Flight Recorder/Mach Airspeed Warning Test Module. To install it, do this task: Flight Recorder/Mach Airspeed Warning Test Module Installation, AMM TASK 31-31-12-400-801.

(f)  
Re-install the Aural Warning Module. To install it, do this task: Aural Warning Module Installation, AMM TASK 31-51-04-400-801.

-------------------------END OF TASK ---------------------------
802.  Mach Airspeed Indicator Airspeed Bugs Do Not Show -Fault Isolation
A.  Description
(1)  This task is for these observed faults:
(a)  
V1 bug does not show on the Mach Airspeed Indicator (MASI).

(b)  
VR bug does not show on the MASI.

NOTE: The fault isolation procedure is the same for either the VR bug or the V1 bug.
B.  Possible Causes
(1)  
No data from the EFIS control panels to the DEUs.

(2)  
SPD REF switch on the engine control module, P2-2.

C.  Related Data
(1)
(WDM 31-62-13).

(2)
(WDM 31-62-23).

EFFECTIVITY

34-16 TASKS 801-802
SIL ALL
Page 202 D633A103-SIL Jun 10/2006

D. Initial Evaluation
(1) Do these steps to prepare for initial evaluation and fault isolation:
(a)  
Set the outer knob on the SPD REF switch on the engine control module to V1.

(b)  
Turn the inner knob on the SPD REF switch on the engine control module clockwise to enter a V1 bug speed.

1) Make sure the V1 bug shows on the MASI.
2) Make sure the V1 digits on the MASI show.

(2)
If the V1 bug does not show on the MASI, then do the Fault Isolation Procedure below.

(3)
If the V1 bug shows on the MASI, then there was an intermittent fault.

E. Fault Isolation Procedure
NOTE: You must do the steps to prepare for fault isolation that are in the Initial Evaluation before you can do these steps.
(1)
Do
this
task:
CDS
BITE
Procedure,
31-62
TASK
801.

(a)  
If the CDS BITE test shows an EFIS data fault, then go to the FIM task for the applicable CDS maintenance message to correct the fault.

1) If the V1 bug shows on the MASI, then you corrected the fault. 2) If the V1 bug does not show on the MASI, then continue.
　
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