TM 10-3930-675-20-1
0040 00-3
BOOM LIFTING/LOWERING TROUBLESHOOTING - CONTINUED
0040 00
Table 1. Error Code 126 - Joystick-to-ECU (790) Failure Troubleshooting Procedures - Continued.
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Error Code 126 - Joystick-to-ECU (790) Failure
- Continued
i. Check
resistance
of
joystick potentiometer: at
joystick pin 9 to joystick pin
10 should be 1.1-1.4k
ohms; joystick pin 9 to
joystick pin 8 should be 1.7-
2.0k ohms; joystick pin 8 to
joystick pin 10 should be
1.7-2.0k ohms.
If resistance is not as specified,
replace joystick (WP 0081 00).
2. Enter “DIAG SERVO 5 (13)”
menu and check voltage of
LIFT/LOWER. If voltage
reads
5V,
perform
the
following steps.
a. Slowly
move
joystick
forward and backward and
observe voltage on menu.
Voltage should be 1-10V.
If voltage suddenly goes out of
range when joystick is moved,
replace joystick (WP 0081 00).
b. Remove ECU (790) cover
from operator’s seat base
and slide ECU mounting
tray out (WP 0079 00).
c. Remove joystick cover.
d. Check
ECU
(790)
connector
1
and
tray
grounding
leads
and
joystick connector X155
for proper connections.
a. Connect
any
loose
or
disconnected
connections.
Push ECU mounting tray in
and install cover.
b. Repair
or
replace
any
damaged connectors (WP
0111 00). Push ECU mounting
tray in and install cover.
