Failure Code [Ca221] Atmospheric Pressure Sensor High Error - Komatsu WA250-6 Shop Manual

SEN03842-00

Failure code [CA221] Atmospheric pressure sensor high error

Action code Failure code
E01
Contents of
• High voltage is detected in atmospheric pressure sensor
trouble
Action of
• Fixes atmospheric pressure and continues operation.
controller
Problem that
• Engine does not start easily.
appears on
• Engine output drops.
machine
• The input state (atmospheric pressure) from the atmospheric pressure sensor can be checked with
the monitoring function (Code: ENGINE, 37400, AMBIENT PRESS).
Related
• The input state (voltage) from the atmospheric pressure sensor can be checked with the monitoring
information
function (Code: ENGINE, 37402, AMBIENT PRESS).
• Method of reproducing failure code: Turn the starting switch ON.
Defective sensor power sup-
1
ply 1 system
Defective atmospheric pres-
2
sure sensor (Internal trouble)
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
26
40-320
Trouble
CA221
Causes
320 Troubleshooting by failure code (Display of code), Part 2
Failure code [CA221] Atmospheric pressure sensor high error
Ambient pressure sensor high error
(Engine controller system)
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) and (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 EC1 (female) (3) –
AMBAIR PRESSURE (female) (3) and
ground
a Prepare with starting switch OFF, then carry out troubleshooting
without turning starting switch ON.
Wiring harness between EC1 (female) (3) –
AMBAIR PRESSURE (female) (3), EC1
(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.
EC1
Between (33) and
(38)
Power supply 4.75 – 5.25 V
Voltage
Resis-
tance
Power supply 4.75 – 5.25 V
WA250, 250PZ-6
1
Voltage
Max. 1 V
Min.
100 kz
Voltage