DIY HVAC Tools

Carrier mini split code AP

Wi-Fi pairing (access point) mode.

  • TypeStatus, not a fault
  • SystemDisplay
  • Can I fix it?Usually a homeowner fix
  • Applies toindoor display, classic two-character codes (38MHRB, 38MGR, 40MAQ)

What AP means on a Carrier

The unit's Wi-Fi module is broadcasting its own network so the app can connect and configure it. It shows AP during setup, and sometimes after a power interruption if the module reboots.

On this platform, AP is a status, not a fault: the unit is telling you what it is doing; nothing is wrong.

What to do

You can almost always clear this yourself with the steps below.

  1. Finish pairing in the manufacturer's app, or wait; the unit exits AP mode on its own after several minutes.
  2. To force it out, turn the unit off and on with the remote.

When to call a technician

This is not a fault. No technician is needed unless it will not clear.

Which Carrier units show AP

This page applies to Carrier Comfort 38MHRB / 40MHHQ, Comfort 38MGR / 40MGQ, Performance 40MAQ / 38MAQ, Infinity 40MPHA / 38MPRA and Carrier multi-zone units on the indoor display, classic two-character codes (38MHRB, 38MGR, 40MAQ). Carrier's own documentation lists AP as "Wi-Fi pairing (access point) mode", the same definition used across the Midea platform (classic codes) it is built on. If your unit shows a code with a different shape (for example a four-character code, or a plain number), it is from a different table; use the lookup with your exact code.

Where Carrier shows this code

indoor display, classic two-character codes (38MHRB, 38MGR, 40MAQ): The code appears on the indoor unit's LED display in place of the set temperature. Some models also blink the indicator lamps in a pattern that matches the code. E codes are faults in the indoor unit or its communication link, F codes are faults on the outdoor side, and P codes are protections: the outdoor unit has stopped itself to prevent damage. EC is the refrigerant leak check.

Other Carrier codes

Same part of the system as AP:

dFDefrost cycle runningCLFilter cleaning reminderFPLow-temperature heating hold (46°F freeze-protection mode)FCForced cooling test modeLLRemote or wired controller lockedcFAnti-cold-air (heating warm-up)CPRemote on/off contact open
E0Indoor unit EEPROM parameter errorE1Communication error between indoor and outdoor unitsE2Zero-crossing signal detection errorE3Indoor fan speed out of control (indoor fan motor fault)E4Indoor room temperature sensor (T1) open or short circuitE5Evaporator coil temperature sensor (T2) open or short circuitECRefrigerant leak detected (low refrigerant charge)F0Overload current protection (compressor over-current)

All Carrier error codes

AP on other brands

The same characters do not always mean the same thing. Check the brand on your unit.

Questions people ask

Is AP on a Carrier mini split an error?

No. AP is a status message: wi-Fi pairing (access point) mode. The unit's Wi-Fi module is broadcasting its own network so the app can connect and configure it.

Do I need a technician for Carrier AP?

You can almost always clear this yourself with the steps below. This is not a fault. No technician is needed unless it will not clear.

Sources

  • Carrier 38MHRB Single Zone Ductless Service Manual SG-38MHRB-01 (Diagnosis and Solution section)
  • Carrier 40MAQ / 38MAQ High-Wall Ductless Service Manual 40MAQ-01SM (Diagnosis and Solution section)
  • Carrier 40MPHA / 38MPRA Infinity High Wall Ductless Service Manual (error code table)

Updated September 2026. Codes and definitions vary by model year. If your manual disagrees with this page, your manual wins. Send a correction.