Failure Code [Ca144] Coolant Temp. Sensor High Error - Komatsu Galeo PC138US-8 Shop Manual

40 Troubleshooting

Failure code [CA144] Coolant temp. sensor high error

User code Failure code
E15
Contents of
• High voltage was detected in coolant temperature sensor circuit.
trouble
Action of
• Fixes coolant temperature (90°C) and continues operation.
controller
Problem that
appears on
machine
• Signal voltage of coolant temperature sensor can be checked with monitoring function.
Related
(Code: 04105 Engine coolant temperature sensor voltage)
information
• Method of reproducing failure code: Turn starting switch ON.
Defective coolant tempera-
1
ture sensor (Internal trouble)
Disconnection in wiring har-
ness (Disconnection in wiring
2
Possible causes
or defective contact in con-
and standard
nector)
value in normal
state
Ground fault in wiring har-
3 ness (Short circuit with GND
circuit)
4 Defective engine controller
Circuit diagram related
PC138US, USLC-8
Trouble
CA144
Cause
Coolant temp. sensor high error
(Engine controller system)
Standard value in normal state/Remarks on troubleshooting
a Prepare with starting switch OFF, then carry out troubleshoot-
ing without turning starting switch ON.
TWTR (male) Coolant temperature
Between (1) – (2)
a Prepare with starting switch OFF, then carry out troubleshoot-
ing without turning starting switch ON.
Wiring harness between CE01 (female) (47)
– TWTR (female) (1)
Wiring harness between CE01 (female) (49)
– TWTR (female) (2)
a Prepare with starting switch OFF, then carry out troubleshoot-
ing without turning starting switch ON.
Wiring harness between CE01 (female) (49)
– TWTR (female) (2) and chassis ground
a Prepare with starting switch OFF, then carry out troubleshoot-
ing without turning starting switch ON.
CE01 (female) Coolant temperature
Between (47) – (49)
SEN02463-01
Resistance
10 – 100°C 0.6 – 20 kz
Resis-
tance
Resis-
tance
Resis-
tance
Resistance
10 – 100°C 0.6 – 20 kz
1
Max. 1 z
Max. 1 z
Min. 1 Mz
21