Mitsubishi Electric mini split error code E5
Indoor unit signal transmitting error (to remote controller).
- TypeFault
- SystemCommunication
- Can I fix it?Homeowner checks, then maybe a tech
What E5 means on a Mitsubishi Electric
The indoor unit cannot send data to the wired remote controller.
On this platform, E5 is a fault: something has failed or is disconnected and needs diagnosis.
Common causes
- A loose or damaged controller cable.
- A failed indoor board.
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.
- Reseat the controller cable.
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
Technician check.
Which Mitsubishi Electric units show E5
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 E5 as "Indoor unit signal transmitting error (to remote controller)", 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 E5:
E5 on other brands
The same characters do not always mean the same thing. Check the brand on your unit.
- Pioneer E5 Evaporator coil temperature sensor (T2) open or short circuit / Over-voltage or under-voltage protection (outdoor display)
- Blueridge E5 Over-current protection / Evaporator coil temperature sensor (T2) open or short circuit
- Gree E5 Over-current protection
- Zone Air E5 Model configuration or mismatch error
- Daikin E5 Compressor motor lock or overload
- Carrier E5 Evaporator coil temperature sensor (T2) open or short circuit
- Trane E5 Model configuration or mismatch error / Indoor unit signal transmitting error (to remote controller)
- Heil E5 Evaporator coil temperature sensor (T2) open or short circuit / Over-current protection
- ACiQ E5 Evaporator coil temperature sensor (T2) open or short circuit / Model configuration or mismatch error
Questions people ask
Can I reset a Mitsubishi Electric E5 code myself?
Yes. Turn the system off at the breaker for five minutes, then restart it. If E5 comes back, the fault is real and needs the checks above.
Is it safe to keep running a Mitsubishi Electric showing E5?
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 E5?
Work through the checks below first; they resolve most cases. If they do not, the repair itself may need a technician. Technician check.
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.