p1
Easy Fix
Mitsubishi Electric · Mini-Splits & Ductless Systems
Intake Air Temperature Sensor Fault
Quick Answer
Error code P1 on your Mitsubishi Electric Mini-Splits & Ductless Systems means: Intake Air Temperature Sensor Fault. This is usually fixable — see the step-by-step guide below.
Affected Models
Applies to all models
Likely Causes
How to Fix It
1
Locate the intake air thermistor near the return air grille of the indoor unit
2
Measure the thermistor resistance with a multimeter (approximately 10K ohms at 77 degrees F)
3
Check the connector at the indoor PCB for corrosion and reseat the connection
4
Inspect the sensor wire routing for pinching or damage
5
Replace the thermistor if resistance is out of the expected range
Pro Tip
This is a common issue that most users can resolve without specialized tools. Try the first step before moving on to more complex solutions.
Parts You May Need
Intake air thermistor
Wire connectors
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