Code [145/Ca145] Coolant Temp. Sensor Low Error - Komatsu 114E-3 Series Shop Manual

SEN00459-01
E-8 Code [145/CA145] Coolant Temp. Sensor Low Error
Error code Failure code
145
Contents of
• Low voltage is detected in coolant temperature sensor signal circuit.
trouble
Action of con-
• Fixes coolant temperature and continues operation.
troller
Problem that
• Exhaust smoke is white
appears on
• Overheat prevention function does not function.
machine
Related infor-
• Method of reproducing failure code: Starting switch ON.
mation
Defective coolant tempera-
1
ture sensor
Ground fault in wiring har-
2 ness (Short circuit with GND
circuit)
Possible causes
and standard
Short circuit in wiring har-
value in normal
3 ness (With another wiring
state
harness)
Defective wiring harness
4
connector
5 Defective engine controller
14
Trouble
CA145
Causes
Abnormally low level in coolant temperature
Standard value in normal state/Remarks on troubleshooting
a Prepare with starting switch OFF, then carry out troubleshooting
without turning starting switch ON.
COOLANT TEMP
Coolant temperature
(male)
Between (A) – (B)
Between (B) –
chassis ground
a Prepare with starting switch OFF, then carry out troubleshooting
without turning starting switch ON.
Wiring harness between J1 (female) (15) –
COOLANT TEMP (female) (B)
a Prepare with starting switch OFF, then carry out troubleshooting
without turning starting switch ON.
Wiring harness among all pins between J1
(female) (15) – J1 (female) (With all connec-
tors of wiring harness disconnected)
Connecting parts among coolant temperature sensor, engine wiring
harness, and engine controller are suspected. Inspect them directly.
• Loose connector, broken lock, broken seal
• Corrosive, bent, broken, forced-in, or extended pin
• Humidity in connector, entry of dirt or dust, poor insulation
a Prepare with starting switch OFF, then carry out troubleshooting
without turning starting switch ON.
J1 (female) Coolant temperature
Between (15) – (38)
Between (15) –
chassis ground
40 Troubleshooting
Resistance
0°C 30 – 37 kz
25°C 9.3 – 10.7 kz
50°C 3.2 – 3.8 kz
80°C 1.0 – 1.3 kz
700 – 800 z
95°C
All range Min. 100 kz
Resis-
tance
Resis-
tance
Resistance
0°C 30 – 37 kz
25°C 9.3 – 10.7 kz
50°C 3.2 – 3.8 kz
80°C 1.0 – 1.3 kz
700 – 800 z
95°C
All range Min. 100 kz
114E-3 Series
1
Min.
100 kz
Min.
100 kz