(2)
(SSM 34-21)

E.  Initial Evaluation
(1)  
For
the
applicable
ADIRS,
do
this
task:
ADIRS
BITE
Procedure,
34-21
TASK
801.

(2)  
If the maintenance message does not show on the CDU and the status code does not show on the ISDU, then there was an intermittent fault.

(3)  
If the maintenance message shows on the CDU and the status code shows on the ISDU, then do the Fault Isolation Procedure below.

EFFECTIVITY SIL ALL  34-21 TASK 811 
D633A103-SIL BOEING PROPRIETARY -Copyright # Unpublished Work -See title page for details  Page 219 Oct 15/2008 

F.  Fault Isolation Procedure
(1) Replace the applicable ADIRU.
These are the tasks:
Air Data Inertial Reference Unit Removal, AMM TASK 34-21-01-000-801,
Air Data Inertial Reference Unit Installation, AMM TASK 34-21-01-400-801.

(a)
Do a check of the condition of the pins and connector of the applicable ADIRU.

(b)
For
the
applicable
ADIRS,
do
this
task:
ADIRS
BITE
Procedure,
34-21
TASK
801.

1)  If the maintenance message does not show on the CDU, and the status code does not show on the ISDU, then you corrected the fault.
2)  If the maintenance message does show on the CDU, and the status code does show on the ISDU, then continue.
(2)  Do this check of the wiring of the program pins for the applicable ADIRU:
(a)  
Remove the ADIRU, to remove it do this task: Air Data Inertial Reference Unit Removal, AMM TASK 34-21-01-000-801.

(b)  
Do a wiring check of these program pins for a ground or an open circuit, per WDM 34-21-11,WDM 34-21-12,WDM 34-21-13,WDM 34-21-21,WDM 34-21-22,WDM 34-21-23,WDM 34-21-24,WDM 34-21-14.

NOTE: Open circuit pins are not shown on the WDMs.

(c)  
For the left ADIRU, do a check of these pins at connector D3687B. For the right ADIRU, do a check of these pins at connector D3693B:

Pin No.  Signal
A2 Mounting Position 1 A3 Mounting Position 2 A5 IR SDI LSB A6 IR SDI MSB C3 GPIRU/IRU select E7 ADIRU/IRU select J5 Enhanced alignment mode select K3 Mag Var model select K9 Mag Var coverage select
(d)  For the left ADIRU, do a check of these pins at connector D3687A. For the right ADIRU, do a check iof these pins at connector D3693A:
Pin No.  Signal
1E A/C IDENT CODE 1/0 1F A/C IDENT CODE 2/0 1G A/C IDENT CODE 4/0
EFFECTIVITY SIL ALL  34-21 TASK 811 
D633A103-SIL BOEING PROPRIETARY -Copyright # Unpublished Work -See title page for details  Page 220 Oct 15/2008 

Pin No.  Signal
1H A/C IDENT CODE 8/0 1J A/C IDENT CODE 16/0 4A A/C IDENT CODE 32/0 4B A/C IDENT CODE 64/0 1K A/C IDENT CODE PARITY
(e)  
Make sure the program pins are connected correctly (WDM 34-21).

(f)  
If you find a problem with the wiring, then do these steps: 1) Repair the wiring. 2) Re-install the ADIRU. To install it, do this task: Air Data Inertial Reference Unit

Installation, AMM TASK 34-21-01-400-801. 3) For
the
applicable
ADIRS,
do
this
task:
ADIRS
BITE
Procedure,
34-21
TASK
801.
4) If the maintenance message does not show on the CDU and the status code does not
show on the ISDU, then you corrected the fault.
-------------------------END OF TASK ---------------------------
812. ADR Program Pin Invalid -Fault Isolation
A.  Description
(1)  
This task is for this maintenance message:

(a)  34-21021 ADR PROG PIN INVLD
　
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