An E6 error code on a Mitsubishi Electric air conditioner means that the indoor and outdoor units can’t talk to each other. This can happen for a number of reasons, such as an odd signal, a broken contact, a short circuit, or a wrongly wired connecting wire. An E6 error code can also be caused by a broken transmitting or receiving circuit on either the indoor or outdoor controller circuit board or a faulty fan motor.

Turning the power on and off again can assist in identifying whether the issue is with the indoor controller board or outside controller circuit board if following these procedures does not address the problem. It may be necessary to replace the indoor controller board or the outdoor controller circuit board if the anomaly continues after turning the power back on.

The indoor/outdoor unit wiring can be faulty and cause an E6 fault. This can be caused by rodent damage, faulty wire or a broken connection. This can be checked visually or checked using a multimeter. Wiring can be simple to be replaced but if the unit is installed when the house was built it could be difficult.

The outdoor fan motor can fail and cause damage to the outdoor Control PC Board. If the fan motor damages the control PC Board the board can no longer communicate with the indoor unit resulting in a Communication error.

Lastly, an E6 error code can also be caused by a bad rush current resistor on the outdoor power circuit board. To see if this is the case, use a tester to check the rush current resistor on the outdoor power circuit board. If an open is found, you may need to replace the resistor. If the Resistor is okay, the Power PC Board may need replacement.

Costs involved in repairing your Mitsubishi Electric air conditioning system

It is important to ensure the correct tests are completed to determine what part requires replacement. It’s an expensive exercise to replace refrigerant when only a damaged wire or PCB is to blame. The cost to fix an E6 fault can range from a fan motor ($600 – $1,200), a PC Board ($900 – $1,800) or replacing a cable ($500 – $2,000). Ensuring the correct parts are diagnosed is vital to make certain you do not waste money on unnecessary parts.

• An E6 error code on a Mitsubishi Electric air conditioner indicates a problem with communication between the indoor and outdoor units.
• Possible causes include abnormal signal receiving, contact failure, short circuit, or miswiring of the connecting wire, a defective transmitting or receiving circuit in either the indoor or outdoor controller circuit board, noise entering the indoor/outdoor unit connecting wire, a defective fan motor and a defective rush current resistor on the outdoor power or control circuit board.
• Try turning off and on the power again to rectify the issue.
• If the problem continues it could be a fan motor, control or Power board issue.

In conclusion, an E6 error code on a Mitsubishi Electric air conditioner means that the indoor and outdoor units can’t talk to each other. Possible causes include an abnormal signal being received, a broken contact, a short circuit, or improper wiring of the connecting wire, a broken transmitting or receiving circuit on either the indoor or outdoor controller circuit board, noise getting into the indoor/outdoor unit’s connecting wire, a faulty fan motor, or a broken rush current resistor on the outdoor power circuit board. To diagnose and rectify this issue, you will need to engage a licenced refrigeration mechanic to investigate the fault.