TM 10-3930-675-20-1
0042 00-3
TOPHANDLER SLEWING TROUBLESHOOTING - CONTINUED
0042 00
Table 1. Error Code 128 - Joystick-to-ECU (790) Failure Troubleshooting Procedures - Continued.
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Error Code 128 - Joystick-to-ECU (790) Failure
- Continued
i. Check
resistance
of
joystick
potentiometer:
joystick pin 9 to joystick pin
10 should be 1.1-1.4k
ohms; joystick pin 9 to
joystick pin 11 should be
1.6-1.9k ohms; joystick pin
11 to joystick pin 10 should
be 1.6-1.9k ohms.
If resistance is not as specified,
replace joystick (WP 0081 00).
j. Replace ECU (790) (WP
0079 00).
2. Enter “DIAG SERVO 6 (13)”
menu and check voltage of
SLEW CW/CCW. If voltage
reads
5V,
perform
the
following steps:
a. Slowly activate slewing
function and move the
joystick right and left.
Observe voltage on menu.
Voltage should be 1-9V.
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, tray grounding
leads, and joystick con-
nector 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.
