TM 5-3805-298-23-1
0098
Table 1. 637 Backup Alarm Diagnostic Codes.
0098
CID FMI CODE
TEST OR INSPECTION
CORRECTIVE ACTION
NOTE
637-3 Backup Alarm Circuit
Voltage Is Above Normal
Always inspect wiring harness connectors that are involved in the circuit.
Poor connections can often be the cause of a problem in an electrical
circuit. Verify that all connections in the circuit are clean and secure and
that all connections are in good condition. If a problem with the
connection is found, correct the problem and verify that this malfunction
or diagnostic code is active before performing this procedure.
Perform open or short-circuit test at each wiring harness connection to
identify the correct wiring harness to replace.
Tag all wiring harnesses to aid in installation.
Perform this test only if condition is active.
DIAGNOSTIC CODE SET CONDITION
Transmission ECM detects voltage of the backup alarm circuit is above normal.
POSSIBLE CAUSE
Lower cab wiring harness is shorted to another power source.
Rear frame wiring harness is shorted to another power source.
Transmission ECM.
Test Step 1. Check for Active
Diagnostic Codes.
1. Connect MSD. Select
Transmission 924H (WP 0008).
2. Turn military light switch to
SER. DRIVE position (TM 5-3805-
298-10).
3. Place transmission control switch
Diagnostic Code 637-3 Active -
Proceed to Test Step 2.
in R position (TM 5-3805-298-10)
and check for active diagnostic
Diagnostic Code 637-3 Not Active -
codes (WP 0008).
Troubleshooting is complete.
Test Step 2. Test for Shorted Rear
Frame Wiring Harness.
1. Turn ignition switch and battery
disconnect switch to OFF position
(TM 5-3805-298-10).
