Failure Code [879Bkb] A/C Outer Sensor Short Circuit - Komatsu PC200-8M0 Shop Manual

SEN06151-00

Failure code [879BKB] A/C Outer sensor Short Circuit

Action
Failure code
level
– 879BKB
q
Detail of failure Air conditioner controller detected short circuit in outside air temperature sensor.
q
The air conditioner controller sends information about the outside air temperature sensor short cir-
Action of con- cuit to the machine monitor via CAN communication.
q
troller Continues control of air conditioner in automatic mode, ignoring data of outside air temperature
sensor.
q
Since there is a short circuit in the air conditioner outside air temperature sensor, outside temper-
Problem on
ature is not counted in automatic mode.
machine
(does not have any effect to the air conditioner in manual mode)
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".
Related infor-
q
Since connector ACECU of the air conditioner controller has small pins and does not have a
mation
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
Defective outside air temperature
1
sensor
Open or short circuit in wiring har-
2
ness
3 Short circuit in wiring harness
Ground fault in wiring harness
4
(contact with ground circuit)
5 Defective air conditioner controller
6 Defective air conditioner unit
48
80-100
Short circuit in air conditioner outside air temperature sensor
Failure
(Machine monitor system)
Procedure, measuring location, criteria and remarks
1. Turn starting switch to OFF position.
2. Disconnect connector P18.
Resistance Between P18 (male) (1) and (2)
1. Turn starting switch to OFF position.
2. Disconnect connector AC01.
a Same as above, if resistance is normal.
Resistance Between AC01 (female) (7) and (8)
a If no failure is found by check for cause 2, this check is not required.
1. Turn starting switch to OFF position.
2. Disconnect connectors P18 and AC01.
Between AC01 (female) (7) and (8), or between
Resistance
P18 (female) (1) and (2)
1. Turn starting switch to OFF position.
2. Disconnect connectors P18 and AC01.
Between ground and AC01 (female) (8) or P18
Resistance
(female) (1)
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.)
If no failure is found by above checks, air conditioner unit may be defective.
Failure code [879BKB] A/C Outer sensor Short Circuit
PC200, 200LC, 220, 220LC-8M0
100 Air conditioner
Approx.
25 °C
1.7 kz
Approx.
25 °C
1.7 kz
Min. 1 Mz
Min. 1 Mz