Mitsubishi Electric mini split error code E2
Remote controller control board fault.
- TypeFault
- SystemControl board
- Can I fix it?Homeowner checks, then maybe a tech
What E2 means on a Mitsubishi Electric
The wired remote controller's own board failed its self-check.
On this platform, E2 is a fault: something has failed or is disconnected and needs diagnosis.
Common causes
- A failed controller.
How to fix it yourself
Work through the checks below first; they resolve most cases. If they do not, the repair itself may need a technician.
- Reset the system: switch the breaker (or the outdoor disconnect) off, wait a full five minutes so the boards fully discharge, then switch it back on and restart from the remote.
Switch off power at the breaker before opening either unit. Capacitors in the outdoor unit hold a charge for several minutes after power is cut.
When to call a technician
Controller replacement.
Which Mitsubishi Electric units show E2
This page applies to Mitsubishi Electric M-Series (MSZ), Mr. Slim (PKA/PCA), Hyper-Heating H2i and MXZ multi-zone units. Mitsubishi Electric's own documentation lists E2 as "Remote controller control board fault", the same definition used across the Mitsubishi Electric it is built on. If your unit shows a code with a different shape (for example a four-character code, or a plain number), it is from a different table; use the lookup with your exact code.
Where Mitsubishi Electric shows this code
Wall units without a wired controller signal a fault by blinking the operation indicator lamp; the code itself shows on a wired controller (MHK/PAR series) or on the wireless remote after entering its check mode (see your manual). On the outdoor unit, the control board LEDs blink the same code. P codes are indoor-unit faults, E codes are communication faults, F codes are outdoor-unit faults and U codes are outdoor-unit and compressor faults.
Other Mitsubishi Electric codes
Same part of the system as E2:
E2 on other brands
The same characters do not always mean the same thing. Check the brand on your unit.
- Pioneer E2 Zero-crossing signal detection error / Communication error between the outdoor unit and the indoor units (outdoor display)
- Blueridge E2 Indoor anti-freeze protection / Zero-crossing signal detection error
- Gree E2 Indoor anti-freeze protection
- Zone Air E2 Indoor fan coil (evaporator) temperature sensor fault (open or short circuit)
- Carrier E2 Zero-crossing signal detection error
- Trane E2 Indoor fan coil (evaporator) temperature sensor fault (open or short circuit) / Remote controller control board fault
- Heil E2 Zero-crossing signal detection error / Indoor anti-freeze protection
- ACiQ E2 Zero-crossing signal detection error / Indoor fan coil (evaporator) temperature sensor fault (open or short circuit)
Questions people ask
Can I reset a Mitsubishi Electric E2 code myself?
Yes. Turn the system off at the breaker for five minutes, then restart it. If E2 comes back, the fault is real and needs the checks above.
Is it safe to keep running a Mitsubishi Electric showing E2?
The unit will usually refuse to run, or run with reduced output, until the fault is cleared. Repeated resets do not fix anything and can mask a problem that is getting worse.
Do I need a technician for Mitsubishi Electric E2?
Work through the checks below first; they resolve most cases. If they do not, the repair itself may need a technician. Controller replacement.
Sources
- Mitsubishi Electric M-Series and Mr. Slim service manuals (self-diagnosis tables)
Updated September 2026. Codes and definitions vary by model year. If your manual disagrees with this page, your manual wins. Send a correction.