Fujitsu · Mini Split
Fujitsu ASTG09 / ASTG12 / AOTG09 / AOTG12 KMTC error codes
Fujitsu GENERAL AIRSTAGE KMTC wall split codes, indoor and outdoor. 24 codes.
Check this is your model before you read on
Check the model number on the data plate before trusting any code on this page. The count is the twenty four codes in the service reference table, which covers the indoor and outdoor units together rather than as two separate tables. The indoor faults are the fan motor, the room and heat exchanger sensors, the indoor main PCB identification, the manual auto switch, the human sensor, the check run, the wired controller and external communication links, and the combination check. The outdoor faults are the inverter and power factor correction circuit, the trip terminal and trip detection, the discharge temperature sensor and the genuine discharge over-temperature, the outdoor heat exchanger and outdoor air sensors, the current sensor, the compressor rotor position, the outdoor fan motor and the four way valve. The list jumps from eighteen to twenty three, and stops at ninety nine before the single letter code A1, so the numbers are not a continuous sequence and a missing number is not a sign of a partial table. A1 is the only letter code here and it is the one to read carefully, because it is a real over-temperature condition rather than a failed sensor, which is what code 71 is.
ASTG09KMTC and ASTG12KMTC indoor units with AOTG09KMTC and AOTG12KMTC outdoor units on R32. A compatible non-polar wired controller shows the code directly on its display. The supplied wireless controller has no screen and shows the same codes as a flashing pattern on the indoor indicator lamps instead. The service reference gives a separate main PCB, control unit and inverter assembly identification for each of the two capacities, so a board from the wrong capacity is a recognised cause of codes 32 and 62.
How to read this code
There are two ways to read a code on this equipment and which one you have changes how you start. With a compatible wired controller, listed in the service reference as UTY-RNRYZ, UTY-RLRY, UTY-RSRY or UTY-RHRY, all of them non-polar two wire units that need a communication kit, the code appears as a number or a letter and number on the controller display. That is the easy case. The controller supplied in the box is a wireless remote with no screen at all, and with that the same fault is shown as a flashing pattern on the three indicator lamps on the indoor unit: the operation lamp is green, the timer lamp is orange and the economy lamp is green. The service reference states that the number in brackets in the service table is the number of flashes, so the full service manual is where the flash count for each code is set out. Read the code off the wired controller wherever you can, because the lamp pattern is a worse way to identify a fault and the one people miscount most often. Two things are worth knowing before you start pulling anything apart. First, the manufacturer is direct about it: an error code identifies the detected condition, it does not automatically identify the failed part, so confirm the wiring, the connectors, the sensor values and the supply before replacing components. Second, the sensor tests on this equipment are resistance checks, not voltage checks, and each of the six thermistors has its own curve, so a reading that looks wrong is often just the wrong table. The three reference values given are 0, 20 and 30 degrees, and the pipe sensors read far lower than the room and discharge sensors, which is the fastest way to tell which sensor is which.
24 codes on this control platform.
24 fault codes
Every one of these means something is wrong. Ordered by how urgent they are.