Komatsu PC130-7, Shop Manual

Page: 283 / 342

PC130-7
20-469
TROUBLESHOOTING
Self-diagnosis
notice
Trouble Abnormality in air mix damper
E45
Contents of
trouble
• Abnormality in the internal and external air servomotor is detected.
Action of
controller
• Stops the internal and external air servomotor.
• If the following condition is satisfied, the trouble is reset.
<Completion of removal of cause> + <Deletion of self-diagnosis notice> +
<Turning starting switch OFF and ON> + <Starting air conditioner>
Related
information
a
Do not connect the power cables to the motor terminals directly to drive the motor. Doing so can dam-
age the motor output shaft and break the motor coils.
Possible causes
and standard
value in normal
state
Cause Standard value in normal state/Remarks on troubleshooting
1
Defective internal and
external air servomotor
(Internal defect)
The internal and external air servomotor may be defective. Check it
directly.
2 Defective fuse (in unit)
If the fuse (in the unit) is broken, the circuit probably has a grounding
fault, etc. Check the related circuits.
3
Disconnection in wiring
harness
(Disconnection in wiring
harness or defective
contact in connector)
a
Prepare with starting switch OFF, then carry out troubleshooting without
turning starting switch.
Wiring harness between M
RF
(female) (1) and
M29 (female) (6)
Resistance Max. 1
z
Wiring harness between M
RF
(female) (3) and
M29 (female) (7)
Resistance
Max. 1
z
Wiring harness between M
RF
(female) (7) and
fuse in unit and M33 (male) (3)
Resistance
Max. 1
z
4
Defective air conditioner
system
If neither of causes 1 and 2 is the cause of the trouble, the air conditioner
system may be defective. See Shop Manual for Chassis Components,
Troubleshooting for air conditioner.
E-32
(1)