Malfunctions during crane operation
14.4 Finding and eliminating malfunctions
Operating Manual GMK6300L 3 112 xxx en 14 - 15
xx.xx.xxxx
 14.4.3             Malfunctions on the main hoist/auxiliary hoist
Malfunction Cause Remedy
Main hoist not working or 
malfunctioning 
Hoist off, lamp in button lights 
up dimly
à Switching on the main hoist, 
p. 11 - 55, 
à Switching on the 
auxiliary hoist
, p. 11 - 58
Dead man's switch not 
actuated
Press dead man's switch
Emergency stop switch 
engaged
à Resetting the emergency stop 
switch
, p. 4 - 24
Fuses F1/1, F3/1, F3/2, F3/5, F3/
6 blown
Replace the blown fuse; 
à p. 14 - 5
Fuse blown on circuit board Replace the blown fuse; 
à p. 14 - 7
Control unit faulty, error 
message is displayed
Acknowledge error message 
once; 
à p. 14 - 36 – if 
error persists, notify 
Manitowoc Crane Care
Fuse F3/7 blown Replace the blown fuse; 
à p. 14 - 9
Only the lifting function 
works
Lowering limit switch 
approached
Leave the shutdown range 
and lift the main hoist
Only the lowering function 
works
Lifting limit switch 
approached, lamp 
# lights up
Leave the shutdown range 
and lower the main hoist
RCL shutdown, lamp 
+ lights 
up
Leave the shutdown range; 
à p. 11 - 37
Fuse F3/3 blown Replace the blown fuse; 
à p. 14 - 9
Lifting, lowering or high-
speed mode function not 
working
Function disabled by ECOS If necessary, acknowledge 
error once and briefly turn off 
the ignition – if error persists, 
notify Manitowoc Crane Care
No Lifting function Fuse RCL F6 faulty Replace the blown fuse; 
à p. 14 - 12
Fuse F3/3 blown  Replace the blown fuse; 
à p. 14 - 9
Lifting or lowering is either 
not possible at all or only at a 
low speed
Speed limited Increase limit; 
à p. 11 - 105
Lifting or lowering function 
cannot be switched off
ECOS malfunction Emergency stop switch; 
à p. 14 - 1
No response to control lever 
movements 
ECOS malfunction concerning 
operating elements in the 
crane cab 
Unrig using hand-held 
control; 
à p. 14 - 59