FieldBench
Mitsubishi codes

Mitsubishi

P1 / P2

Protect

Indoor thermistors

Return or pipe sensor.

Walk P1 / P2 in Diagnose

2 plates — walk the one on the cabinet

First check

1 Which sensor is this code?

On Mitsubishi MSZ-FS P1 / P2 is a specific thermistor — indoor return/pipe, outdoor coil, discharge, or ambient. Unplug that sensor and ohm it vs the OEM temperature/resistance chart. Ohms vs M-series chart, connector on indoor board.

Expect: Ohms move with temperature. Not open, not shorted.

The rest of the walkthrough is Diagnose.

On the plates

  • Ohms vs M-series chart, connector on indoor board.
  • Ohms vs M-series GL chart, connector on the indoor board.
  • Do not look for an i-see thermistor that is not in this head.

Plates that use P1 / P2