Toshiba Fault Codes Troubleshooting Guide

If your Toshiba high-wall air conditioner is showing unusual behaviour, flashing lights, or won’t operate as expected, it could be trying to tell you something. Toshiba air conditioning units come equipped with a self-diagnosis system that uses check codes to indicate faults.

This guide will help you understand how to use the remote control in service mode, interpret the codes, and determine the necessary next steps for repair or maintenance.

How to Use the Toshiba Remote Controller in Service Mode

Your Toshiba air conditioner allows you to access diagnostic codes using the remote control. Here’s how:

Press the [CHECK] button with a pen or pencil to enter service mode. A “ ” icon appears on the display.
Press the [ON] or [OFF] button to start the self-diagnosis process.
The system will scan for up to 52 error codes. If no faults are found, the unit beeps once and the display changes.
If a fault is detected:
- – The indoor unit beeps continuously for 10 seconds
- – All indicator lamps flash rapidly (5Hz)
- – A two-digit alphanumeric check code appears on the remote display
Press [START/STOP] to exit service mode when done.
To clear stored error codes, press [CLR] and send check code “7F”.

Toshiba Air Conditioner Error Codes & Meaning

Here is a breakdown of common check codes and what each one indicates:

Indoor Unit Faults

Fault	Cause	Action
Room Temperature Sensor Fault (TA)	Disconnected, short-circuit, or failure	Check and replace sensor or P.C. board
Heat Exchanger Sensor Fault (TC / TCj)	Disconnected, out of place, or faulty	Inspect placement, replace sensor or P.C. board
Indoor Fan Error	Fan motor fault or control board issue	Check motor operation and replace board if needed
General Indoor PCB Fault	Internal failure	Replace indoor P.C. board

Outdoor Unit Faults

Fault	Cause	Action
Outdoor Heat Exchanger Sensor (TE / TS) Fault	Short-circuit or disconnection	Check sensors and P.C. board
Discharge Temperature Sensor (TD) Fault	Faulty sensor or wiring	Inspect sensor; replace if damaged
Outdoor Fan System Error	Fan motor or drive system issue	Replace fan motor or P.C. board
Outdoor Temp Sensor (TO) Fault	Faulty reading	Check sensor and connections

Electrical & Compressor Faults

Fault	Cause	Action
Inverter Overcurrent	Short circuit or overload	Replace outdoor P.C. board
Position Detection Error	Fault in compressor windings	Replace compressor or control board
Compressor Does Not Start	Current not detected after startup	Check wiring or compressor
Compressor Drive Output Error	Severe internal fault	Check voltage, gas pressure, or replace compressor
High Discharge Temperature (>117°C)	Overload, gas leak, sensor fault	Check TD sensor, recharge gas, inspect P.M.V.
4-Way Valve Inverse Fault	Heating error (TC sensor drop)	Check 4-way valve function

Signal & Communication Errors

Fault	Cause	Action
Serial Signal Not Returning	Wiring issue or gas shortage	Check cable connections, inverter board, and charge level
Serial Signal Stops Midway	Compressor or P.C. board issue	Replace relevant board or repair wiring

For quick error code diagnosis, we’ve built a simple troubleshooting tool, just select your error code and instantly get the details you need.

Fault Code Troubleshooting Tool

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Fault Code Troubleshooting Tool

Select Fault Code:

Important Notes After Diagnosis

Turn off the power supply after service and restart the system to reset temporary conditions.
Permanent faults must be cleared manually using the remote (CLR → 7F).
Errors stored in the system remain in memory until cleared — even after power loss.

Toshiba Offical Manual Link: https://www.toshiba-aircon.co.uk/assets/uploads/pdf/eoi/Fault_Diagnosis_From_Infa_Red_2.pdf