Komatsu Failure Code 879AKA

Action level	Failure code	Failure	Air Conditioner Recirculation Air Temperature Sensor Open Circuit (Machine monitor system)
–	879AKA
Details of failure	Air conditioner controller detects open circuit in recirculation air temperature sensor.
Action of controller	Air conditioner controller transmits open circuit information of recirculation air temperature sensor to machine monitor by CAN communication. Stops air conditioner when in automatic air conditioner mode.
Phenomenon on machine	Since air conditioner recirculation air temperature sensor has open circuit, automatic air conditioner does not operate. (Air conditioner can be operated in manual mode.)
Related information	After repairing, check if the failure code is cleared by the following procedure. Procedure: Turn starting switch to ON position. Check if this failure code is displayed on electrical system failure record screen in “SERVICE MODE” of machine monitor. Since connector of air conditioner recirculation air temperature sensor cannot be checked when it is mounted on machine, troubleshooting cannot be performed.

No.

Cause

Procedure, measuring location, criteria and remarks

Defective air conditioner controller

Air conditioner controller may be defective.

(In case of an internal defect, troubleshooting is impossible as an assembly. Replace whole assembly.)

Defective air conditioner unit

Air conditioner controller may be defective. (In case of an internal defect, troubleshooting is impossible as an assembly. Replace whole assembly.)

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