Failure of the Weather Radar Control Unit (System 1)

TASK 34-41-00-810-812-A
Failure of the Weather Radar Control Unit (System 1)

1. Possible Causes

XCVR-WEATHER RADAR, 1 [1SQ1]
CTL UNIT-WEATHER RADAR [3SQ]
wiring of the CONTROL BUS from the weather radar control unit (3SQ) to the weather radar transceiver 1 (1SQ1)

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
AMM 34-41-00-740-002	BITE Test of the Weather Radar
ASM 344101
AMM 34-41-12-000-001	Removal of the Weather Radar Control Unit
AMM 34-41-12-400-001	Installation of the Weather Radar Control Unit
AMM 34-41-33-000-004	Removal of the Weather Radar Transceiver
AMM 34-41-33-400-003	Installation of the Weather Radar Transceiver

3. Fault Confirmation
Subtask 34-41-00-740-070-A

A. Test
(1) Do the BITE test of the weather radar AMM 34-41-00-740-002.

4. Fault Isolation
Subtask 34-41-00-810-064-A ** ON A/C NOT FOR ALL

A. If the BITE test gives the maintenance message RADAR 1 CONTROL UNIT:

(1) If the fault continues:

replace the CTL UNIT-WEATHER RADAR [3SQ] AMM 34-41-12-000-001 and AMM 34-41-12-400-001.

(a) If the fault continues:

do a check and repair the wiring of the CONTROL BUS from the weather radar control unit (3SQ) to the weather radar transceiver 1 (1SQ1) ASM 344101.

Subtask 34-41-00-810-064-C ** ON A/C NOT FOR ALL

A. If the BITE test gives the maintenance message WXR CNT PNL (3SQ)/WXR1 (1SQ1):

(1) If the fault continues:

replace the CTL UNIT-WEATHER RADAR [3SQ] AMM 34-41-12-000-001 and AMM 34-41-12-400-001.

(a) If the fault continues:

do a check and repair the wiring of the CONTROL BUS from the weather radar control unit (3SQ) to the weather radar transceiver 1 (1SQ1) ASM 344101.

Subtask 34-41-00-740-071-A

B. Do the test given in Para. 3.

[Rev.8 from Aug 2018] 2026.04.04 04:33:05 UTC