Haier AW07EH2VHA Service Manual page 110

Testing Communication Circuit
If an Error E7 occurs, perform the following test to determine
if the indoor control board is functioning properly to send data
to the outdoor unit.
Perform this test with the unit powered and all wiring
connected between indoor and outdoor unit.
Make sure all wiring between the indoor and outdoor unit
are correct. There should no splices between the indoor and
outdoor unit wiring connecting terminals 1 or 3. Make sure
wiring is correct, before performing this test.
1. Measure the DC voltage between terminals 1 and 3 on the
indoor terminal block.
2. The voltage should fluctuate between 8VDC and 23VDC.
The fluctuating signal indicates a good communication
path.
3. If the voltage does not fluctuate, and the wiring is good,
the indoor board is defective.
Replacing WiFi Module
1. Unplug existing WiFi module.
2. Insert new WiFi module.
3. Replace the wifi passcode sticker.
4. Pair the unit to account.
I-8
Topic Title Testing
CONSOLE TECHNICAL OVERVIEW