Fujitsu Error Code E7:00: Outdoor Ambient Sensor Fault

Severity
Warning
Type
digital display
Estimated repair cost: $100 — $250 (parts + labor)
Warning: The outdoor unit's ambient temperature sensor has failed or is disconnected, causing the system to stop running. This prevents heating or cooling.

How to Fix Fujitsu Code E7:00

  1. Step 1: Power cycle the unit by turning off the breaker that supplies power to the outdoor unit for 5 minutes, then turn it back on. This may reset the system and clear a temporary error.
  2. Step 2: Visually inspect the wiring around the outdoor unit. Look for any obvious signs of damage to the wiring or connectors. Do not touch any wires or components.
  3. Step 3: If the error persists after power cycling and visual inspection, contact a qualified HVAC technician to diagnose and repair the system.

How to Reset Fujitsu Code E7:00

  1. Turn off the unit using the remote control or wall controller.
  2. Turn off the circuit breaker for the outdoor and indoor units. Wait 60 seconds.
  3. Restore power at the breaker.
  4. 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 E7:00 Mean?

The E7:00 error code on your Fujitsu mini-split system indicates a problem with the outdoor ambient temperature sensor. This sensor is responsible for measuring the outside air temperature, which the system uses to adjust its operation for efficient heating and cooling. When the system detects a fault with this sensor, it shuts down to prevent potential damage or inefficient operation. This sensor is important because the system relies on accurate outdoor temperature readings to properly control refrigerant flow and compressor speed. Without this information, the system may not be able to provide adequate heating or cooling, or it could even ice up in cooling mode or struggle to defrost in heating mode. The system is locked out until the fault is resolved.

Common Causes

  • Faulty outdoor ambient temperature sensor
  • Loose or corroded wiring connections at the sensor or the main outdoor unit control board
  • Wiring harness damage (rodent damage, cuts, etc.)
  • Defective outdoor unit control board

Diagnostic Steps

If... Check Expected
System displays E7:00 error Measure the resistance of the outdoor ambient temperature sensor at the outdoor unit control board connector. Refer to the Fujitsu service manual for the correct pins. Resistance should match the temperature/resistance chart in the service manual. An open or short indicates a faulty sensor.
Sensor resistance is out of range Inspect the wiring harness and connectors between the sensor and the outdoor unit control board for continuity and shorts to ground. Wiring should have continuity and no shorts to ground.
Wiring is intact, and sensor resistance is incorrect Check the voltage supply to the sensor from the outdoor control board. Typically 5VDC. If no voltage is present, the control board is likely faulty.

Applicable Fujitsu Models

Replacement Parts

Part OEM Number Est. Cost Where to Buy
Outdoor Ambient Temperature Sensor 9316429017
Outdoor Unit Control Board

Related Codes on Same Models

Other codes that affect the same Fujitsu model families as E7:00.

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
E5:00 Indoor Coil Sensor Short Warning
E6:00 Outdoor Coil Sensor Fault Warning
E8:00 Indoor Fan Motor Fault Warning
E9:00 Drain Pump / Float Switch Warning
EE:00 Communication Error (Multi-System) Warning