Komatsu PC200-8M0, Shop Manual, Page: 1214 / 1254

100 Air conditioner
Failure code [879GKX] Refrigerant Abnormality
80-100
56
PC200, 200LC, 220, 220LC-8M0
SEN06151-00
Failure code [879GKX] Refrigerant Abnormality
Action
level
Failure code
Failure
Refrigerant (dual) pressure switch abnormality
(Machine monitor system)
L01 879GKX
Detail of failure q Air conditioner controller detected that dual pressure switch was OFF (abnormal).
Action of con-
troller
q
The air conditioner controller sends information about the refrigerant pressure abnormality to the
machine monitor via CAN communication.
q
The air conditioner controller turns OFF compressor clutch relay, since refrigerant pressure is ab-
normal.
(air conditioner compressor stops)
Problem on
machine
q
Air conditioner (cooling) does not work
Related infor-
mation
q
Method of reproducing failure code: Turn starting switch to ON position.
q Check whether this failure code is displayed in the "Electrical Systems" (electrical systems abnor-
mality record) screen in the service mode of the machine monitor.
q
For connectors etc., see "Parts and connectors layout".
q
Since connector ACECU of the air conditioner controller has small pins and does not have a
T-adapter, perform troubleshooting by using the intermediate connector (Although the intermediate
connector does not have a T-adapter either, it does have large pins).
q To replace the air conditioner harness between air conditioner controller connector ACECU and
intermediate controller, the air conditioner unit must be replaced.
Cause Procedure, measuring location, criteria and remarks
1
Defective refrigerant (dual) pres-
sure switch
1. See "Testing (dual) pressure switch for refrigerant".
k
When replacing the dual pressure switch, be sure to collect refriger-
ant in advance. See "Caution for refrigerant"
2
Open circuit in wiring harness
(wire breakage or defective con-
tact of connector)
1. Turn starting switch to OFF position.
2. Disconnect connectors AC01 and AC05.
Resistance
Between P17 (female) (1) and AC01 (female) (6) Max. 1
z
Between P17 (female) (2) and ground
a
Looseness and rust of T06
Max. 1
z
3 Defective air conditioner controller
If no failures are found by the above checks, the air conditioner controller may
be defective. (Since this is an internal defect, troubleshooting cannot be per-
formed.)
4 Defective air conditioner unit If no failure is found by above checks, air conditioner unit may be defective.