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38

Outdoor air temperature sensor abnormal — RUN LED flashes 3 times, TIMER LED flashes 8 times

Mitsubishi Heavy Industries · Air Conditioners

What does 38 mean?

The outdoor air temperature sensor is reporting abnormal readings, such as –55°C or lower (or higher) continuously, which impacts the unit's control and efficiency.

Common Causes

  • Outdoor air temperature sensor wire is disconnected
  • Poor connector connections for the sensor
  • Faulty outdoor PCB

Repair Steps & Checklist

Click steps to track your progress.

  1. 1

    Turn off the main power to the unit.

  2. 2

    Locate the outdoor air temperature sensor, typically on the outdoor unit.

  3. 3

    Inspect the sensor wire for any visible disconnections, cuts, or damage.

  4. 4

    Check the connector connections for the sensor, ensuring they are securely plugged in and free from corrosion.

  5. 5

    Reconnect any loose wires or connectors firmly.

Browse all codes in this manual (110)
Verified technical data. Last updated: April 2026

Related Faults

01Power source faulty — RUN LED OFF, TIMER LED flashes 1 time05Wired remote control wiring error — RUN LED OFF, TIMER LED flashes 5 times35Cooling high pressure control activated — RUN LED flashes 3 times, TIMER LED flashes 5 times
Source: Mitsubishi Heavy Industries Air Conditioners
Open Manual (Page 53)Search more codes in this manual