Troubleshooting
Controller
MB1 I/O-
board
(
-3N2
)
defective?
Binary outputs:
BA 1→ Cooling release
BA 2→ Solenoid valve
(-7Y1
)
large plate evaporator
BA 3→ Solenoid valve
(-7Y2
),
small plate evaporator
Yes
Replace controller MB1 I/O-board
(chap. 8.8.1)
Check acc. to chap. 4.4
No
Capillary tubes blocked?
Yes
Have replaced the capillary tubes
(chap. 10.4)
No
Loss of refrigerant?
Yes
Have the leak closed
24
Service Manual KBF (E5.2) 04-2015