Trane Mini Split 2-TIME BLINK Error Code

Updated 2026-08-29 · review status: manual-verified Last verified: 2026-08-29

Quick answer

2-TIME BLINK on Trane mini splits means indoor coil or room temperature thermistor trouble - the control detected a short or open circuit in those indoor sensor signals. Clear the area around the indoor unit, power cycle once, and stop; recurring blinks are sensor/PCB work for a technician.

Severity: medium · DIY difficulty: beginner

Safety

Stop here: electrical or inverter work is technician-only. Do not open panels, test capacitors, touch wiring, connect gauges, add refrigerant, or keep resetting the system.

What 2-TIME BLINK means

Trane's troubleshooting table lists 2-TIME BLINK as indoor coil thermistor or room temperature thermistor trouble. The failure-mode table says the control detects a short or open circuit in those indoor thermistor signals, stops the fan, and blinks the upper OPERATION INDICATOR lamp 2 times with a 2.5-second pause.

Code meaning varies by series

  • Trane ML series (Mitsubishi-built NTXWMT/NAXWMT) service manual, failure-mode recall table: Room temperature thermistor or indoor coil thermistor short/open circuit detected; same pattern appears in the 9-4 troubleshooting check table with a 2-time blink / 2.5-second OFF cadence

Causes, ranked

  1. 1. Temporary control or sensor glitch that clears on reset occasional diy-ok

    Check: Confirm the indoor unit has open airflow (filters clean, grilles unblocked), turn the system off, power cycle once at the breaker or disconnect if you can do that safely.

    Fix: If the code clears and stays clear, no further action; if it returns, stop resetting and call a technician.

  2. 2. Room temperature thermistor (RT11) short or open circuit occasional pro-only

    Check: Requires disconnecting the sensor and measuring resistance against the manual's characteristic chart.

    Fix: Technician: test/replace the room temperature thermistor.

  3. 3. Indoor coil thermistor (RT12/RT13) short or open circuit occasional pro-only

    Check: Requires opening the indoor cabinet and measuring the coil sensor.

    Fix: Technician: test/replace the indoor coil thermistor.

  4. 4. Indoor control PCB misreading a good sensor occasional pro-only

    Check: Only distinguishable with multimeter checks of the sensor against PCB test points.

    Fix: Technician: verify wiring and connectors, replace the indoor control PCB if sensors test good.

Related codes

trane/3-time-blink · trane/4-time-blink · trane/5-time-blink · trane/6-time-blink · trane/7-time-blink · trane/upper-lamp-0-5-second-blink

Commonly searched as: "trane 2-time blink" · "trane error code 2-time blink" · "trane air conditioner 2-time blink"

Sources

  • Trane error codes (upper lamp blink table) - SplitAtlas, sourced from Trane MyLinkDrive NTXWMT-A111A(B) Service Manual Section 9 — verified 2026-08-29
  • Mitsubishi Electric / American Standard NAXSMT-A111AA (Trane ML-series equivalent) Service Manual, 9-4 Troubleshooting Check Table — verified 2026-08-29