BOLDR HOME

Mitsubishi Mini-Split Error Codes: Full List and Meanings

by Dua Jones April 22, 2026

Mitsubishi mini-splits display error codes through a blinking LED pattern on the indoor unit's front panel. The operation light, timer light, and sometimes a third indicator blink in specific sequences to communicate what fault the system has detected. This guide covers the most common Mitsubishi error codes, what they mean, and what to do for each one.

How to Read Mitsubishi Error Codes

When a fault occurs, Mitsubishi indoor units blink the OPERATION (green) and/or TIMER (orange) LED lights in a pattern. Count the number of blinks in each sequence, then use the table below to identify the error. The pattern repeats after a pause — count one complete sequence.

For units with a wired remote controller or display, the error code appears as a two-character alphanumeric code (e.g., E6, U6, P8).

Klima - Smart Home Thermostat for Mini-splits, Air Conditioners and Heatpumps

Compatible with all brands of ACs and Mini-Splits Automate Climate Management Control remotely Reduce Energy Consumption Monitor bills in realtime

Try Now

Common Mitsubishi Error Codes

Error Code	LED Blinks	Meaning	First Step
E0	Operation: 1	Indoor unit auto-restart after power failure	Normal — unit restarted automatically
E1	Operation: 1 / Timer: 1	Outdoor unit overcurrent	Reset at breaker; call tech if recurring
E2	Operation: 2 / Timer: 1	Zero cross detection failure	Call technician — control board issue
E3	Operation: 3 / Timer: 1	Fan motor fault (indoor)	Check for obstructions; call tech
E4	Operation: 4 / Timer: 1	Freeze protection / freeze stat	Clean filter; check for coil freeze
E6	Operation: 6 / Timer: 1	Communication error (indoor to outdoor)	Reset at breaker; check wire connections
E7	Operation: 7 / Timer: 1	Outdoor fan motor fault	Check outdoor unit for obstructions; call tech
E8	Operation: 8 / Timer: 1	Outdoor unit overcurrent protection	Reset at breaker; call tech if recurring
E9	Operation: 9 / Timer: 1	Expansion valve fault	Call technician
P1	Timer: 1	Intake air temperature sensor fault	Call technician — thermistor replacement
P2 / P9	Timer: 2 / Timer: 9	Pipe temperature sensor fault	Call technician — thermistor replacement
P4	Timer: 4	Drain sensor fault / blocked drain	Clear the condensate drain line
P6	Timer: 6	Freeze protection — pipe temperature too low	Clean filter; check airflow; call tech
P8	Timer: 8	Outdoor unit high pressure / overheating	Clear outdoor unit airflow; call tech if recurring
U6	Operation: 6 / Timer: 6	Simultaneous indoor/outdoor unit fault	Call technician — may indicate refrigerant or compressor issue

What to Do When an Error Code Appears

Step 1: Note the blink pattern exactly before doing anything else. Count both the OPERATION and TIMER blinks.
Step 2: Try a breaker reset — off for 30 seconds, then on. Wait 3 minutes before operating.
Step 3: If the same code returns after reset, the system is detecting a real fault. Contact a Mitsubishi Diamond Contractor for diagnosis.
Step 4: For drain-related codes (P4), clearing the condensate drain may resolve the error without a technician.

Frequently Asked Questions

How do I find out what error code my Mitsubishi mini-split is showing?

Count the number of times the OPERATION (green) LED blinks before it pauses, and separately count the TIMER (orange) LED blinks. The combination identifies the error. Units with wired controllers display the code directly as a two-character alphanumeric (E6, P4, etc.). Your owner's manual also contains a complete error code list for your specific model.

Will a reset clear the error code permanently?

A reset clears the code from memory, but if the underlying cause is not fixed, the same code will return when the system detects the fault again. A code that clears with a reset but does not return may have been a temporary glitch. A code that returns immediately or consistently indicates a real hardware issue.