HVACopedia

Carrier · Mini-split

J6 Low pressure protection

High severity Carrier DLCM(R/H)B multi-zone outdoor

What the control is telling you

Same fault as PC31. Shown on the 48K high heat model.

Applies to: DLCMHBH48EAK (48K high heat) only

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 Carrier DLCM(R/H)B multi-zone outdoor

DLCMHBH24CAKDLCMHBH30DAKDLCMHBH36DAKDLCMHBH48EAKDLCMRBH18BAKDLCMRBH36DAKDLCMRBH48EAK

Other codes on the same units

  • J0 Outdoor coil overheat in cooling
  • J1 Indoor coil temperature protection in heating
  • J2 Discharge temperature protection
  • J3 PFC module protection
  • J4 Main board to IPM board communication error
  • J5 High pressure protection
  • J8 AC voltage protection
  • LC06 IPM high temperature / PFC frequency limit

Save it for the next call

Star this code in the HVACopedia app and keep the whole library on your phone for jobs with no signal.

Open the app

Source: DLCMRBH/DLCMHBH Multi-Zone Outdoor Service Manual (sold as Midea, Carrier and Viessmann Vitocal 200-S; Viessmann doc 6225551-03, 12/2024), Table 24 Outdoor Unit Error Display (48 High Heat only) p.27; diagnosis p.62-63. Summarized in our own words; check the original manual for your model.

Homeowner looking at this code? See what it means for you and when to call a technician.

For licensed technicians. Gas, electrical and refrigerant work must be done by a qualified, licensed person. Shut off power and gas before servicing, never bypass a safety control, and follow the manufacturer’s manual for the exact model; it and local codes always take priority. HVACopedia is not affiliated with any manufacturer; brand and model names only identify the equipment.