Panasonic WH-ADF0309J3E5CM Service Manual page 240

24.2.2 E01 & E02
E01 - Remote Controller Reception Error
E02 - Remote Controller Transmission Error
When remote controller is set to sub (Slave) remote controller:

If only one remote controller is connected to indoor unit, this remote controller
must set to main remote controller. (Wireless remote controller set the switch
at wireless receiver)
Group control:

Confirm the grouped indoor units no more than eight units.

Check all indoor unit power supply status.

Make sure group control setting is executed.

Group control wiring changed after setting is done.

Grouped control wire (Black & White) shorted, mis-wiring, wrong contact or
grounded.
Setting Related:

CHK and TEST pin shorted.

EEPROM no installed or defect when main power switched ON.

Remote controller on check mode.

Remote controller itself defect.

Indoor unit PCB malfunction.
EEPROM
Wired Remote Controller
CHK Pin
TEST Pin
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