Electrolux W4400H Service Manual page 49

IO COMMUNICATION
Communication between programme unit A1 and one of the I/O cards
has been interfered with or interrupted, or incorrect configuration of
the I/O cards.
If the power is on, be very careful when working on the machine.
Try to restart the machine (i.e. reset the error code) by pressing START. If
the error returns, troubleshoot as follows:
1. Perform a communication test using the test box. Refer to the manual "Instructions
for Clarus Communication Tests".
OK LED on test box
The motor controller or cabling for the motor controller is probably defective.
Troubleshooting
Defective LEDs on test box
Troubleshoot according to the manual "Instructions for
Clarus Communication Tests".
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