SEN00459-01 40 Troubleshooting
12 114E-3 Series
E-7 Code [144/CA144] Coolant Temp. Sensor High Error 1
Error code Failure code
Trouble Abnormally high level in coolant Temperature
144 CA144
Contents of
trouble
• High voltage is detected in coolant temperature sensor signal circuit.
Action of con-
troller
• Fixes coolant temperature and continues operation.
Problem that
appears on
machine
• Exhaust smoke is white
• Overheat prevention function does not function.
Related infor-
mation
• Method of reproducing failure code: Starting switch ON.
Possible causes
and standard
value in normal
state
Causes Standard value in normal state/Remarks on troubleshooting
1
Defective coolant tempera-
ture sensor
a Prepare with starting switch OFF, then carry out troubleshooting
without turning starting switch ON.
COOLANT TEMP
(male)
Coolant temperature Resistance
Between (A) – (B)
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
95°C 700 – 800 z
2
Disconnection in wiring har-
ness (Disconnection in wiring
or defective contact in con-
nector)
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)
Resis-
tance
Max. 10 z
Wiring harness between J1 (female) (38) –
COOLANT TEMP (female) (A)
Resis-
tance
Max. 10 z
3
Short circuit in wiring har-
ness (With another wiring
harness)
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)
Resis-
tance
Min.
100 kz
4
Defective wiring harness
connector
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
5 Defective engine controller
a Prepare with starting switch OFF, then carry out troubleshooting
without turning starting switch ON.
J1 (female) Coolant temperature Resistance
Between (15) – (38)
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
95°C 700 – 800 z
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