TM 5-3805-298-23-1
0098
Table 1. 637 Backup Alarm Diagnostic Codes - Continued.
098
CID FMI CODE
TEST OR INSPECTION
CORRECTIVE ACTION
3. Place transmission control switch
637-5 Backup Alarm Circuit
Diagnostic Code 637-5 Active -
in R position (TM 5-3805-298-10)
Proceed to Test Step 2.
Current Below Normal -
and check for active diagnostic
Continued
Diagnostic Code 637-5 Not Active -
codes (WP 0008).
Troubleshooting is complete.
Test Step 2. Test for Faulty Backup
Alarm.
1. Turn ignition switch and battery
disconnect switch to OFF position
(TM 5-3805-298-10).
2. Disconnect connector M-C4
(WP 0012, Figure 75) from backup
alarm.
3. Ensure the military light switch is in
SER. DRIVE position (TM 5-3805-
298-10).
4. Ensure transmission control switch
is in R position (TM 5-3805-298-
10).
5. Turn battery disconnect switch and
ignition switch to ON position
(TM 5-3805-298-10).
6. Using digital multimeter
Voltage 18 to 26 V - Replace backup
(WP 0174), test for voltage
alarm (WP 0279).
between connector M-C4
Proceed to Test Step 5.
(WP 0012, Figure 75) terminal 1
Voltage Less Than 18 V - Proceed to
and terminal 2.
Test Step 3.
Test Step 3. Test Lower Cab Wiring
Harness for High Resistance or
Open.
1. Turn ignition switch and battery
disconnect switch to OFF position
(TM 5-3805-298-10).
2. Install a jumper wire between
terminal 1 and terminal 2 of
connector M-C4 (WP 0012,
Figure 75).
3. Remove blackout backup alarm
relay (TM 5-3805-298-10) from
C-C31 (WP 0012, Figure 74).
4. Install a jumper wire between
terminal B3 and terminal B5 of
connector C-C31 (WP 0012,
Figure 74).
5. Remove left lower cab access
panels (WP 0347).
0098-5
