Failure Code [Ca145] Coolant Temp Sens Low Error - Komatsu PC200-8M0 Shop Manual

SEN06133-00

Failure code [CA145] Coolant Temp Sens Low Error

Action
Failure code
level
L01 CA145
q
Detail of failure Low voltage appears in signal circuit of coolant temperature sensor .
Action of con-
q
Takes coolant temperature to be at fixed value and allows engine to run.
troller
q
Problem on Engine does not start easily at low temperature.
machine q Overheat prevention function does not work.
q
Input voltage from engine coolant temperature sensor can be checked with monitoring function.
(Code: 04105 (V))
q
Temperature sensed by engine coolant temperature sensor can be checked with monitoring func-
Related infor- tion.
mation (Code: 04107(°C) )
q
Method of reproducing failure code: Turn starting switch to ON position.
q
If temperature sensor connector is disconnected, this failure code is not displayed but failure code
[CA144] for "High Error" is displayed.
Cause
Defective wiring harness connec-
1
tor
Defective coolant temperature
2
sensor
3 Short circuit in wiring harness
Ground fault in wiring harness
4
(contact with ground circuit)
5 Defective engine controller
30
40-301
Coolant Temperature Sensor Low Error
Failure
(Engine controller system)
Procedure, measuring location, criteria and remarks
See descriptions of wiring harness and connectors in "c: Electrical equipment"
in "Checks before troubleshooting" of "General information on troubleshoot-
ing", and check them.
1. Turn starting switch to OFF position.
2. Disconnect connector COOLANT TEMP, and connect socket to male side.
a If coolant temperature sensor has resistance of 700 z - 37 kz with coolant
temperature above 0 °C, regard coolant temperature sensor as normal.
Between COOLANT
TEMP (male) (A) and (B)
a Coolant temperature
-Resistaure charac-
teristics
Between (B) and ground
1. Turn starting switch to OFF position.
2. Disconnect connector ECM and connect T-adapters to female side.
Between ECM (female) (15) and (38) (Coolant tem-
perature: Min. 0 °C)
a Use "Coolant temperature-Resistance charac-
teristics" table shown above as resistance crite-
ria.
1. Turn starting switch to OFF position.
2. Disconnect connectors ECM and COOLANT TEMP, and connect
T-adapter to female side of ECM.
Between ECM (female) (15) and ground
If no failure is found by above checks, engine controller is defective. (Since
this is an internal defect, troubleshooting cannot be performed.)
301 Troubleshooting by failure code, Part 1

Failure code [CA145] Coolant Temp Sens Low Error

0 °C Resistance
25 °C Resistance
50 °C Resistance
80 °C Resistance
95 °C Resistance
Whole cool-
ant temper- Resistance
ature range
PC200, 200LC, 220, 220LC-8M0
30 to 37 kz
9.3 to 10.7 kz
3.2 to 3.8 kz
1.0 to 1.3 kz
700 to 800 z
Min. 100 kz
Resis-
700 z to 37 kz
tance
Resis-
Min. 100 kz
tance