Inverter Overcurrent Protection

What it means

This code appears on Toshiba residential split air conditioners when the fault code is read with the remote check function. It means the outdoor inverter board detected overcurrent in the compressor drive circuit and stopped the compressor at once to protect the power module (IPM) and the compressor windings. The outdoor unit stops and may retry, and the fault locks in if it repeats. The same code can mean something else on other brands, and Toshiba commercial units use different codes.

Models covered: Toshiba residential split air conditioners (RAC) that show a two-character check code through the remote check function; Toshiba commercial units use different codes.

Related codes: 16171C1D1F

Symptoms4

• The outdoor unit stops as the compressor starts, or seconds later.
• The indoor unit lamps blink and code 14 is found with the remote check function.
• Warm air while the indoor fan keeps running.
• In severe cases the breaker trips.

Possible causes5

• A failed power module (IPM) or outdoor inverter board, the most common cause.
• Loose or burned compressor wiring terminals.
• Severe voltage fluctuation or low supply voltage.
• High compressor load from a dirty condenser or a closed service valve.
• Shorted compressor windings or poor winding insulation.

How to diagnose6

1. Read the code with the remote check function: press and hold the check button, then step through the codes with the timer button until the indoor unit beeps continuously; the code shown then is the fault. Steps vary slightly by remote, so follow the owner's manual.
2. Turn the unit off at the breaker and do not restart it again and again, as this can add damage.
3. Switch off at the breaker before opening any panel; the outdoor unit and its inverter board keep a dangerous charge for a while after switch-off.
4. The technician checks the condenser is clean, the service valves are open and the compressor terminals are sound.
5. The technician measures supply voltage and tests the power module and inverter board using the manufacturer method.
6. The technician tests the compressor windings and insulation to decide whether the board or the compressor is at fault.

How to fix6

1. Wash the condenser and open the service valves if closed.
2. Tighten or replace burned compressor terminals.
3. Fit a voltage protector and fix the supply problem.
4. Replace the inverter board or power module at an authorized service center.
5. Replace the compressor if proven faulty, with evacuation and recharge by a licensed technician.
6. Run the unit, monitor current and confirm the code does not return.

The cost is low for a terminal or dirty condenser, rises steeply for an inverter board, and is highest for an inverter compressor.

Prices are rough estimates including the part and the technician’s fee, and vary with brand, model and part source.
Prices last updated: September 2026

Frequently asked questions