Electrolux W455 H Service Manual page 31

Fault code 28, CPU/DLCU LOW LEVEL
The DLCU contains a mechanical level monitor which ensures that there is
no water in the machine when the lock opens. To ensure that the level
monitor functions correctly, the mechanical level monitor is compared with a
nominal value generated by the CPU, which is compared with the electronic
level check.
When the water level exceeds the nominal value, a check is made to ensure
that the mechanical level monitor is switched on, and if so, a fault code is
generated.
Reason:
• The level controller can be damaged:
• Cross talk in the level controller electrical system.
• Leakage in the level controller's air hoses.
• Incorrect nominal value, possibly caused by a fault in the electronic level
controller.
Action:
• Check the level controller function. (Switch-on level = 40 mm, switch-off
level = 15 mm Wg)
• Check the cables and their connections. The voltage across the level
controller should be 0 V when the water level is < 15 mm Wg and 5 V
when water level is > 40 mm Wg.
• Check that the level hoses are not blocked. Blow clean all the hoses in
the level system.
Fault code 31, COOL FLANGE HIGH TEMP.
This fault code is generated by the motor control. There is a temperature
sensor (NTC) mounted on the motor control cooling flange next to the
power transistors in the output stage. If the temperature of the cooling
flange gets too high (> 90°C) the fault code will be set to protect the
transistors.
Troubleshooting
31
438 9047-81/02