E2 refers to a lack of drainage in documented AQUA models. The correct drain path depends on the machine type; do not use the same height for all washing machines.
The AQUA Japanese FAQ includes hose and outlet checks. Confirm the configuration before changing the setup.
What may be visible from the outside
With the washing machine stopped, check whether the hose is crushed, rises higher than the manual allows, or is inserted in a way that blocks its end. Also look to see whether the home drain has a visible blockage.
A gravity drain and a pump drain are not necessarily installed the same way. Do not copy the setup from a front-loading machine or tilt the unit to drain water out. Also, do not open a filter whose existence or access is not described in your reference manual.
Trapped water can prevent it from moving on to the spin cycle. If the external restriction does not explain E2, request an inspection without attributing it to the spin motor. E1 for supply and U3 for spin retain their own checks when those are the messages shown.
Keep a note of where the hose ends and whether the water went down; it helps review the drain path.