Daikin Mini Split E9 Error Code

What E9 means

E9 means malfunction of the electronic expansion valve coil (or its drive circuit): the outdoor unit cannot step the EEV to the commanded position, so refrigerant metering fails. Daikin's SM-TS3 self-diagnosis table lists E9 as 'malfunction of electronic expansion valve coil'; split and VRV service documentation describe EEV coil or wiring/driver defects. One blog source wrongly recasts E9 as indoor/outdoor communication failure - Daikin's own documentation and the main code references agree on the EEV reading.

First checks before service

This page currently documents the safe reset triage. If the code returns, use the linked source manual or a qualified technician for code-specific diagnosis.

1. 1. One-time fault event (power disturbance or transient sensor reading) common DIY

   Check: Power-cycle at the breaker/disconnect (or unplug for CPAP), restore, and run the system while watching for the code.

   Fix: If the code does not return after a full run cycle, the fault was transient — monitor, no repair needed.

2. 2. Fault persists after a clean reset occasional pro only

   Check: If the code returns immediately or every session, note the conditions (startup, heating, after rain).

   Fix: A persisting code points at the component the manual assigns to this code — that repair is technician territory.