Fujitsu Error Code E5:00: Indoor Coil Sensor Short
How to Fix Fujitsu Code E5:00
- Step 1: Turn the unit off and then back on. Sometimes a simple reset can clear a temporary error.
- Step 2: Check the wiring connections at the indoor unit where the wires enter the unit. Look for any obvious signs of damage or loose connections. Do not open the unit, just visually inspect the external wiring.
- Step 3: If the error persists after resetting and checking the external wiring, contact a qualified HVAC technician to diagnose and repair the issue.
How to Reset Fujitsu Code E5:00
- Turn off the unit using the remote control or wall controller.
- Turn off the circuit breaker for the outdoor and indoor units. Wait 60 seconds.
- Restore power at the breaker.
- Turn the unit on with the remote control. If the error returns, the fault needs professional diagnosis.
Resetting clears the code from the display but does not fix the underlying fault. If the code returns after reset, proceed to the diagnostic steps above.
What Does Fujitsu Error Code E5:00 Mean?
The E5:00 error code on your Fujitsu mini-split indicates a problem with the temperature sensor located on the indoor coil. This sensor monitors the coil's temperature to prevent freezing during cooling or overheating during heating. A 'short' means the sensor is sending an incorrect signal to the control board, suggesting an extreme temperature even if the coil is not actually that hot or cold. Because the system can't reliably monitor the coil temperature, it shuts down to prevent potential damage to the compressor or other components. This isn't a dangerous situation like a gas leak, but it does mean your system won't provide heating or cooling until the issue is fixed. A faulty sensor, wiring issues, or even a problem with the main control board can trigger this error.
Common Causes
- Faulty indoor coil temperature sensor
- Loose or damaged wiring connecting the sensor to the control board
- Moisture or corrosion on the sensor or wiring connections
- Defective main control board
Diagnostic Steps
| If... | Check | Expected |
|---|---|---|
| Unit displays E5:00 error | Measure resistance of the indoor coil temperature sensor at the control board connector | Specific resistance value based on ambient temperature (refer to Fujitsu service manual). An open or short indicates a faulty sensor. |
| Sensor resistance is out of range | Inspect wiring harness and connectors between the sensor and the control board for damage or corrosion | Wiring and connectors are intact and free of corrosion. |
| Wiring appears OK, but resistance is still out of range | Replace the indoor coil temperature sensor | Error code clears after sensor replacement. |
| Error persists after sensor replacement | Check the voltage at the sensor input on the main control board | Stable voltage as specified in the service manual. Lack of voltage or unstable voltage indicates a faulty control board. |
Applicable Fujitsu Models
Replacement Parts
| Part | OEM Number | Est. Cost | Where to Buy |
|---|---|---|---|
| Indoor coil temperature sensor | — | — | — |
| Main control board | — | — | — |
Related Codes on Same Models
Other codes that affect the same Fujitsu model families as E5:00.
| Code | Description | Severity |
|---|---|---|
| E0:00 | Communication Error (Indoor to Remote) | Warning |
| E1:00 | Communication Error (Indoor to Outdoor) | Warning |
| E2:00 | Room Temp Sensor Open Circuit | Warning |
| E3:00 | Room Temp Sensor Short Circuit | Warning |
| E4:00 | Indoor Coil Sensor Open | Warning |
| E6:00 | Outdoor Coil Sensor Fault | Warning |
| E7:00 | Outdoor Ambient Sensor Fault | Warning |
| E8:00 | Indoor Fan Motor Fault | Warning |
| E9:00 | Drain Pump / Float Switch | Warning |
| EE:00 | Communication Error (Multi-System) | Warning |