ODU P2 Low pressure protection (outdoor board)

What the control is telling you

Outdoor board display. Indoor shows PC31 (old P6).

Applies to: DLCMRBH / DLCMHBH multi-zone outdoor units 18-48K (Midea, Carrier, Viessmann Vitocal 200-S)

Test and repair steps

1. Safety kill power at the disconnect and wait for the inverter capacitors to discharge before touching boards or wiring.
2. Check the low-pressure switch wiring to the main board.
3. Unplug the switch and measure it. A good switch reads 0 ohms at rest; open = replace it.
4. Check the outdoor temperature is not below the operating range.
5. Make sure both service valves are fully open.
6. In cooling, check the indoor fans run (see the fan faults if not).
7. Check for low charge or a leak and repair. If all good, replace the outdoor main board.

Models that show this code

7 models in Viessmann Vitocal 200-S DLCM(R/H)B multi-zone outdoor

Other codes on the same units

• ODU LC Low ambient cooling mode
• ODU LP Low outdoor temperature protection (outdoor board)
• ODU P0 Compressor top overheat (outdoor board)
• ODU P1 High pressure protection (outdoor board)
• ODU P3 Current overload (outdoor board)
• ODU P4 Discharge temperature protection (outdoor board)
• ODU P5 Condenser high temperature (outdoor board)
• ODU P6 Inverter module (IPM) fault (outdoor board)