Komatsu 114E-3 Series, Shop Manual

Page: 236 / 342

SEN00460-01 40 Troubleshooting
36
114E-3 Series
E-46 Code [757/CA757] All Engine Controller Data Lost Error 1
Error code Failure code
Trouble Loss of all data in engine controller
757 CA757
Contents of
trouble
• All data in engine controller are lost.
Action of con-
troller
• None in particular.
Problem that
appears on
machine
• Engine stops and sometimes cannot be started.
• Monitoring function of machine monitor (engine controller system) may not work normally.
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 related system If another failure code is indicated, carry out troubleshooting for it.
2
Loose or corroded battery
terminal
Inspect battery terminal directly for loose and corrosion.
3 Defective battery voltage
a
Prepare with starting switch OFF, then turn starting switch OFF
and START and carry out troubleshooting.
Battery (1 piece) Starting switch Voltage
Between (+) – (–)
terminals
OFF Min. 12 V
START Min. 6.2 V
4 Defective fuse No. 19 If fuse is burnt out, circuit probably has ground fault.
5
Defective relay for engine
controller power supply
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.
6
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 F01-19 – R23, R24
(female) (3) Resis-
tance
Max. 10
z
Wiring harness between R23, R24 (female)
(5) – J3 (female) (3) Resis-
tance
Max. 10
z
Wiring harness between J3 (female) (1) –
chassis ground (T12) Resis-
tance
Max. 10
z
7
Defective wiring harness
connector
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
8 Defective engine controller
a
Prepare with starting switch OFF, then turn starting switch ON
and START and carry out troubleshooting.
J3 (female) Starting switch Voltage
Between (3) – (1)
ON Min. 24 V
START Min. 12 V