Troubleshooting For Fresh/Recirc Air Changeover - Komatsu PC200-8M0 Shop Manual

100 Air conditioner

Troubleshooting for FRESH/RECIRC air changeover

Troubleshooting for FRESH/RECIRC air changeover
Failure FRESH/RECIRC air cannot be changed over
q
When FRESH/RECIRC air selector switch of machine monitor is operated, recirculated or fresh air
Problem on
does not change over.
machine
(FRESH/RECIRC air changeover door (damper) does not rotate)
q
FRESH/RECIRC air changeover is not checked with self-diagnosis function.
q
Referring to "Testing FRESH/RECIRC air changeover", operate the FRESH/RECIRC air selector
switch and check operation of FRESH/RECIRC air changeover door (damper).
q
For each connector, see "Parts and connectors layout".
a The T-adapter is not prepared for the connector.
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
Related infor-
connector does not have a T-adapter either, it does have large pins).
mation
q
To replace the air conditioner harness between air conditioner controller connector ACECU and
intermediate controller, the air conditioner unit must be replaced.
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
Troubleshooting cannot be performed since the connector portion of the servomotor cannot be
checked while it is installed on machine.
Cause
Defective fuse No. 18 in fuse box
1
F01
Open circuit in wiring harness
2 (wire breakage or defective con-
tact of connector)
Ground fault in wiring harness
3
(contact with ground circuit)
4 Defective air conditioner controller
5 Defective air conditioner unit
Defective machine monitor
6
(defective switch)
PC200, 200LC, 220, 220LC-8M0
Procedure, measuring location, criteria and remarks
If fuse is blown, circuit probably has ground fault.
a Connector [5] installed on machine cannot be disconnected since it is on
the rear side of the air conditioner unit.
1. Turn starting switch to OFF position.
2. Disconnect connector AC02.
3. Remove fuse No. 18 of F01.
Resistance Between F01-18 and AC02 (female) (3)
1. Turn starting switch to OFF position.
2. Disconnect connector AC02.
3. Remove fuse No. 18 of F01.
Between F01-18 and ground, or between AC02
Resistance
(female) (3) and ground
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 failures are found by the above checks, the air conditioner unit may be
defective. (Since this is an internal defect, troubleshooting cannot be per-
formed.)
1. Turn starting switch to ON position.
2. Display the air conditioner operation screen on the machine monitor.
Press FRESH/RECIRC air selector switch.
SEN06151-00
Max. 1 z
Max. 1 z
Display of Recirc/Fresh
changes.
65
80-100