Troubleshooting For Power Supply And Can Communication System (Air Conditioner Does Not Operate) - Komatsu PC200-8M0 Shop Manual

SEN06151-00

Troubleshooting for power supply and CAN communication system (Air conditioner does not operate)

Troubleshooting for power supply and CAN communication system (Air
conditioner does not operate)
Failure Air conditioner does not operate due to power supply system failure.
q
Problem on [DAZQKR] is displayed on the operation screen of machine monitor.
q
machine No air blows out (Blower motor does not rotate).
q
If failure code [DAZQKR] is displayed on machine monitor, perform this troubleshooting first.
a The machine monitor, engine controller, pump controller, and air conditioner controller are connect-
ed via CAN communication.
q
"DAZQKR" is displayed on operation screen of machine monitor in the following cases. In this sec-
tion, 1) and 2) of the following are explained.
1) The air conditioner controller is receiving no power.
2) The air conditioner controller is malfunctioning.
3) No communication is possible between the air conditioner controller and the machine monitor.
a For 3), see failure code [DAZQKR].
q Turn starting switch to ON position and check whether failure code [DAZQKR] is displayed on ma-
chine monitor and whether CAN communication condition is abnormal. This type of abnormal sta-
tus indicates that CAN communication cannot be performed between the air conditioner controller
Related infor-
mation above the air conditioner unit and the machine monitor.
q
Referring to "Parts and connectors layout", check fuse No. 10 (5 A) in fuse box F01 for breakage.
q
Ground cable of air conditioner is connected in machine wiring harness together with electrical
equipment of machine.
q
For each connector, see "Parts and connectors layout".
q
In cases where fuses are blown when the A/C switch is pressed, see "Troubleshooting for compres-
sor and refrigerant system."
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 in-
termediate controller, the air conditioner unit must be replaced.
Cause
1 Defective wiring harness (ground)
2 Blown fuse
3 Defective wiring harness
Ground fault in wiring harness
4
(contact with ground circuit)
58
80-100
Procedure, measuring location, criteria and remarks
1. Turn starting switch to OFF position.
2. Turn battery disconnect switch to OFF position.
3. Disconnect connector AC02.
Between (1) (black) on harness side of connector
Resistance
AC02 and chassis ground
1. Turn starting switch to OFF position.
2. Referring to "Parts and connectors layout", check fuse No. 10 (5 A) in fuse
box F01 for breakage.
a If fuse described in related information is blown, replace it.
1. Turn starting switch to OFF position.
2. Turn battery disconnect switch to OFF position.
3. Disconnect connector AC02.
4. Turn battery disconnect switch to ON position.
5. Turn starting switch to ON position.
Between connector AC02 (female) (4) (red) and (1)
Voltage
(black)
a If the fuse is blown again during the above test, carry out the following pro-
cedure.
1. Turn starting switch to OFF position.
2. Turn battery disconnect switch to OFF position.
3. Disconnect connector AC02.
4. Remove fuse No. 10 of fuse box F01.
Between ground and connector AC02 (female) (4)
Resistance
(red) or F01-10
100 Air conditioner
Max. 1 z
20 to 30 V
Min. 1 Mz
PC200, 200LC, 220, 220LC-8M0