TM 10-3930-675-20-1
0040 00-12
BOOM LIFTING/LOWERING TROUBLESHOOTING - CONTINUED
0040 00
Table 7. Error Code 157 - Lift Cylinder Boom Down Valve, Wiring Circuit Failure
Troubleshooting Procedures - Continued.
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Error Code 157 - Lift Cylinder Boom Down
Valve, Wiring Circuit Failure - Continued
b. Check continuity between
connector X159 pin 1 and
connector X158 pin 3.
If continuity is not present,
repair or replace connectors (WP
0111 00).
4. Perform voltage check at
connector block X154 pin 3.
a. If 20-25V is present, check
continuity between con-
nector X154 pin 3 and ECU
(790) connector 2 pin 9.
If continuity is not present,
repair or replace connectors (WP
0111 00).
b. If no voltage is present,
check continuity between
connector X154 pin 3 and
emergency stop switch 250
pin 2.
If continuity is not present,
repair or replace connectors (WP
0111 00).
5. Move operator’s cab to
transport position and remove
transmission
rear
access
cover (WP 0135 00).
6. Disconnect electrical con-
nector from boom down
solenoid 6004 and perform
voltage check. If voltage is
not present, perform the
following continuity checks.
If 20-25V is present at connector
6004, replace boom down
solenoid (WP 0169 00).
Check continuity between
connector X158 pin 3 and
solenoid 6004 connector
pin
1
and
between
connector X158 pin 4 and
solenoid 6004 connector
pin 2.
a. If continuity is not present,
repair or replace connectors
(WP 0111 00).
b. If wiring harness must be
replaced, notify SRA.
7. Enter “DIAG SERVO 9 (13)”
menu and check current of
OUTPUT LOWER. Current
should
be
present
with
joystick activated to lower
boom.
If current is not present, replace
ECU (790) (WP 0079 00).
