Communication Error

Communication Error

Communication error codes by model:

1x Operation & 1x Timer:

RL2 series, RLS3 series, RLS2 series, RLB/RLXB series, RLF series, RLF1 series, LUAS1 series, LMAS series, LZBS series, LZAS series, LPAS series, RGLX series, RLE series

2x Timer / 3x Timer / 4x Timer:

RLS series, RLXS series, CQ series, RQ series, R2 series, RL series, RML series, RMLQ series, CLX series, CLX1 series, RLX series, RLXQ series, CL1 series, CL series, RLQ series

5x Operation & Continuous Timer flash:

ABU18RULX, ABU24RULX & ABU36RSLX

1 flash on LED A, 1 flash on LED B, 1 flash on LED E & 1 flash on LED F:

AOU36RLXFZH & AOU45RLXFZ

2 flashes on Power Mode LED, Solid Error LED, 1 flash L1, 1 flash L2, solid L5 & solid L6 / 2 flashes on Power Mode LED, Solid Error LED, 1 flash L1, 1 flash L2, solid L4:

AOU30RLXEH

E113 / E114 outdoor LED:

AOU48RLXFZ & AOU48RLXFZ1

00 / 01 / 11 Wired remote:

UTY-RNBYU, UTY-RNNUM, UTY-RVNUM, UTY-RSNUM, UTY-DMMUM & UTY-RNRUZ series, UTY-RSRY, UTY-RHRY

 Communication Error Troubleshooting Checklist

1. Pull disconnect for 5 minutes, check to see if error code reappears.
2. If error code reappears, check for loose field wires between the indoor and outdoor units.
3. Incoming AC voltage to the condenser should be between 187vAC & 253vAC for all models except systems: 9CQ, 12CQ, 9RQ, 12RQ, 9R2, 12R2, 9RL2, & 12RL2 (115vAC).  AC voltage should be the same coming into the condenser as well as at the indoor unit on terminals 1 & 2.
4. Conduct a DC volt to determine if the problem is coming from the outdoor unit, indoor unit, or field wiring.
5. With power off to the disconnect, remove the # 3 field wire from the outdoor unit terminal block. Once removed, turn the disconnect back on and with your meter in DC voltage check the wire to ground. Take note whether the voltage is steady or fluctuating.
6. Next, check the terminal # 3 screw to ground and note if voltage is steady or fluctuating again.
7. In this test, voltage should be constantly fluctuating 60-130 vDC. Wherever the steady voltage is coming from is where the problem could possibly be.
8. Kill power to the disconnect again and place the # 3 field wire back in the terminal block.
9. Conduct the same test at the indoor and note if the DC volts are steady or fluctuating. The problem lies where the steady voltage is. However, not all indoor units will fluctuate on the terminal # 3 screw to ground. For a list of these models click here.
10. Example, steady voltage on both ends of the # 3 field wire could indicate a possible short or issue with the wire. Check for wire nuts, splices, etc. Steady voltage on the terminal block could indicate a problem with a board or component on either the outdoor or indoor unit.
11. Articles on troubleshooting boards and components can be found here: Outdoor fan motor check, Indoor fan motor check, ACTPM check, IPM check, Diode bridge check, Compressor check, EEV Check

 In troubleshooting the electrical boards you find that one must be replaced, How-To videos can be found here.

Here is an example on how to remove boards from a multi-zone and large cassette condensers:

Here is an example on how to remove the board from single zone model condensers:

 Here is an example on how to remove the boards from a 5 board setup condenser:

Disclaimer:

Always Practice Safety First. Turn off power before commencing any work.  In order to perform some of these tests an electrical and/or refrigerant license is required. We strongly advise to check the Service manual for more detailed explanation. If you are not sure about these recommendations please contact our technical support line at 866-952-8324. Fujitsu General America, Inc. is not responsible for any damage and/or harm caused by unsafe acts during these test.