Trane mini split error codes
Trane sells ductless units from two makers. The 4TXK, 4MXW and related hi-wall inverter series are built on the TCL platform; the NTX series sold through the Trane and Mitsubishi Electric partnership uses Mitsubishi's code set. Several codes exist in both tables with different meanings, so check the model number on the indoor unit's label.
Covers: 4TXK / 4MXW hi-wall inverter, 4TYK / 4MYW, Trane-Mitsubishi Electric NTX series.
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73 codes. Type to filter the list.
No code matches that. Check the characters (b and 6, 0 and o, and E and F are easy to confuse) or try another brand.
How Trane shows error codes
4TXK / 4MXW series: The indoor display shows the code in place of the set temperature. E codes are faults: something has failed and needs diagnosis. P, H, d and F codes are protections: the system stopped or throttled itself to prevent damage, and many clear on their own once conditions return to normal.
Trane-Mitsubishi Electric NTX series: Wall units without a wired controller signal a fault by blinking the operation indicator lamp; the code itself shows on a wired controller (MHK/PAR series) or on the wireless remote after entering its check mode (see your manual). On the outdoor unit, the control board LEDs blink the same code. P codes are indoor-unit faults, E codes are communication faults, F codes are outdoor-unit faults and U codes are outdoor-unit and compressor faults.
Brands built on the same platform
These brands share a code table with Trane because the same factory builds them, so their pages describe the same faults: ACiQ, American Standard, Ameristar, Mitsubishi Electric, TCL, Zone Air.
Sources
- Trane Mini Split HW Inverter Service Manual (4TXK / 4MXW), SVM027A-EN, 2024, error code table
- Mitsubishi Electric M-Series service manuals (self-diagnosis tables)
Updated September 2026. Manufacturer site: www.trane.com/residential/en/products/ductless-systems