Komatsu 114E-3 Series - E-12 Code [187;CA187] Sensor Sup. 2 Volt. Low Error

SEN00459-01 40 Troubleshooting
22 114E-3 Series
E-12 Code [187/CA187] Sensor Sup. 2 Volt. Low Error 1
Error code Failure code
Trouble Abnormally low level in sensor power supply 2
187 CA187
Contents of
trouble
• Low voltage is detected in sensor power supply 2 circuit.
Action of con-
troller
• Fixes charge pressure and charge temperature, and continues operation.
• Limits output and continues operation.
Problem that
appears on
machine
• Engine output drops.
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 sensor or wiring
harness
a Disconnect connector with starting switch OFF, then turn starting
switch ON and carry out troubleshooting.
Disconnect devices at
right in order. If mark
E of failure code dis-
appears after repro-
duction operation is
conducted, that
device or wiring har-
ness has a defect in
it.
Boost pressure, tem-
perature sensor
BOOST PRESS &
IMT
Common rail pres-
sure sensor
FUEL RAIL PRESS
Bkup sensor CAM SENSOR
Engine wiring
harness
J1
2
Defective wiring harness
connector
Connecting parts among each 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
3 Defective engine controller
If causes 1 and 2 are not detected, engine controller may be defec-
tive. (Since trouble is in system, troubleshooting cannot be carried
out.)