Code [221/Ca221] Ambient Air Press. Sensor High Error - Komatsu 114E-3 Series Shop Manual

SEN00459-01
E-13 Code [221/CA221] Ambient Air Press. Sensor High Error
Error code Failure code
221
Contents of
• High voltage is detected in atmospheric pressure sensor
trouble
Action of con-
• Fixes atmospheric pressure and continues operation.
troller
Problem that
• Engine output drops.
appears on
• Starting performance is poor.
machine
Related infor-
• Method of reproducing failure code: Starting switch ON.
mation
Defective sensor power sup-
1
ply 1 system
Defective atmospheric pres-
2
sure sensor
Hot short (Short circuit with
3 5V, 24V circuit) in wiring har-
ness
Possible causes
and standard
value in normal
state
Short circuit in wiring har-
4 ness (With another wiring
harness)
Defective wiring harness
5
connector
6 Defective engine controller
24
Trouble
CA221
Causes
Abnormally high level in atompspheric
Standard value in normal state/Remarks on troubleshooting
If failure code [CA386] is indicated simultaneously, carry out trouble-
shooting for it first.
a Prepare with starting switch OFF, then turn starting switch ON
and carry out troubleshooting.
AMBAIR PRESSURE
Between (1) – (2)
Voltage is measured with wiring harness connected. Accordingly, if
voltage is abnormal, check wiring harness and controller, too, for
another cause of trouble, and then judge.
a Prepare with starting switch OFF, then turn starting switch ON
and carry out troubleshooting.
Wiring harness between J1 (female) (3) –
AMBAIR PRESSURE (female) (3)
a Prepare with starting switch OFF, then carry out troubleshooting
without turning starting switch ON.
Wiring harness between J1 (female) (3) –
AMBAIR PRESSURE (female) (3) and J1
(female) (33) – AMBAIR PRESSURE
(female) (1)
Connecting parts among atmospheric pressure sensor, engine wir-
ing 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
a Prepare with starting switch OFF, then turn starting switch ON
and carry out troubleshooting.
J1
Between (33) – (38)
40 Troubleshooting
Power supply 4.75 – 5.25 V
Voltage
Resis-
tance
Power supply 4.75 – 5.25 V
114E-3 Series
1
Voltage
Max. 1 V
Min.
100 kz
Voltage