How do I fix error code E Sd on a LG refrigerators?

1. undefined: Check all loose connections in the harness between main PCB and Sub PCB. 2. undefined: Check voltage at Sub CON1 pins 8–33; expected 0V or 5V. If out of range, check Sub PCB connection. If connection OK, change Sub PCB. 3. undefined: Check voltage at Sub CON1 pins 10–33; expected 0V or 5V. If out of range, check Sub PCB connection. If connection OK, change Sub PCB. 4. undefined: Check voltage at Main CON3 pins 1–15; expected 0V or 5V. If out of range, check display PCB for loose connection. If loose, repair. If OK, change Display PCB. 5. undefined: Check voltage at Main CON3 pins 3–15; expected 0V or 5V. If out of range, check display PCB for loose connection. If loose, repair. If OK, change Display PCB. 6. undefined: If all checks are normal, explain to customer.

LG Refrigerators

Error Code E Sd

Sub PCB communication error

Moderate

Address soon - your appliance may not work properly

How to Fix

1
Check all loose connections in the harness between main PCB and Sub PCB.
2
Check voltage at Sub CON1 pins 8–33; expected 0V or 5V. If out of range, check Sub PCB connection. If connection OK, change Sub PCB.
3
Check voltage at Sub CON1 pins 10–33; expected 0V or 5V. If out of range, check Sub PCB connection. If connection OK, change Sub PCB.
4
Check voltage at Main CON3 pins 1–15; expected 0V or 5V. If out of range, check display PCB for loose connection. If loose, repair. If OK, change Display PCB.
5
Check voltage at Main CON3 pins 3–15; expected 0V or 5V. If out of range, check display PCB for loose connection. If loose, repair. If OK, change Display PCB.
6
If all checks are normal, explain to customer.