Code [441/Ca441] Supply Voltage Low Error - Komatsu 114E-3 Series Shop Manual

SEN00460-01
E-36 Code [441/CA441] Supply Voltage Low Error
Error code Failure code
441
Contents of trou-
• Low voltage occurred in controller power supply circuit.
ble
Action of
• None in particular.
controller
Problem that
• Engine stops
appears
• Starting performance is poor
on machine
Related informa-
• Method of reproducing failure code: Starting switch ON.
tion
Loose, corroded battery ter-
1
minal
2 Defective battery voltage
3 Defective fuse No. 19
Defective relay for engine
4
controller power supply
Disconnection in wiring har-
ness (Disconnection in wiring
5
or defective contact in con-
nector)
Possible
causes and
standard value
in normal state
Ground fault in wiring har-
6 ness (Short circuit with GND
circuit)
Short circuit in wiring harness
7
(With another wiring harness)
Defective wiring harness con-
8
nector
18
Trouble Abnormally low power supply voltage
CA441
Causes Standard value in normal state/Remarks on troubleshooting
Inspect battery terminal directly for loose and corrosion.
a Prepare with starting switch OFF, then turn starting switch OFF
and START and carry out troubleshooting.
Battery (1 piece)
Between (+) – (–)
terminals
If fuse is burnt out, circuit probably has ground fault. (See cause 6.)
a Prepare with starting switch OFF, then turn starting switch ON and
carry out troubleshooting.
Replace relays for engine controller power supply (R23, R24) with
other relays. If mark E of failure code disappears after reproduction
operation is conducted, that relay has a defect.
a Prepare with starting switch OFF, then carry out troubleshooting
without turning starting switch ON.
Wiring harness between F01-19 – R23, R24
(female) (3)
Wiring harness between R23, R24 (female)
(5) – J3 (female) (3)
Wiring harness between J3 (female) (1) –
chassis ground (T12)
a Prepare with starting switch OFF, then carry out troubleshooting
without turning starting switch ON.
Wiring harness between F01-19 – R23, R24
(female) (3) and chassis ground
Wiring harness between R23, R24 (female)
(5) – J3 (female) (3) and chassis ground
a Prepare with starting switch OFF, then carry out troubleshooting
without turning starting switch ON.
Wiring harness among all pins between J3
(female) (3) – J3 (female) (1) (With battery
terminal disconnected)
Wiring harness among all pins between J3
(female) (3) – J2 (female) (With battery termi-
nal disconnected)
Wiring harness among all pins between J3
(female) (1) – J2 (female) (With battery termi-
nal disconnected)
Connecting parts among fuse No. 19, engine unit 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
40 Troubleshooting
Starting switch
OFF Min. 12 V
START Min. 6.2 V
Resis-
tance
Resis-
tance
Resis-
tance
Resis-
tance
Resis-
tance
Resis-
tance
Resis-
tance
Resis-
tance
114E-3 Series
1
Voltage
Max. 10 z
Max. 10 z
Max. 10 z
Min.
100 kz
Max. 10 z
Min.
100 kz
Min.
100 kz
Min.
100 kz