Failure Code [Ca122] Charge Pressure Sensor High Error - Komatsu WA250-6 Shop Manual

SEN03842-00

Failure code [CA122] Charge pressure sensor high error

Action code Failure code
E03
Contents of
• High voltage is detected in pressure signal circuit of boost pressure sensor and temperature sensor.
trouble
Action of • Fixes charge pressure (boost pressure) and continues operation.
controller
• Turns the centralized warning lamp and alarm buzzer ON.
Problem that
appears on
• Engine output drops.
machine
• The input state (boost pressure) from the charge pressure sensor (boost pressure sensor) can be
checked with the monitoring function (Code: ENGINE, 36500, CHG PRESS-A).
Related
• The input state (voltage) from the charge pressure sensor (boost pressure sensor) can be checked
information
with the monitoring function (Code: ENGINE, 36502, CHG PRESS-A).
• Method of reproducing failure code: Turn the starting switch ON.
Defective sensor power sup-
1
ply 2 system
Defective boost pressure
sensor and temperature sen-
2
sors [pressure signal system]
(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
6
40-320
Trouble
CA122
Causes
320 Troubleshooting by failure code (Display of code), Part 2
Failure code [CA122] Charge pressure sensor high error
Charge pressure sensor high error
(Engine controller system)
Standard value in normal state/Remarks on troubleshooting
If failure code [CA227] 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.
BOOST PRESS & IMT
Between (2) and (4)
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) (44) –
BOOST PRESS & IMT (female) (1) and
ground
a Prepare with starting switch OFF, then carry out troubleshooting
without turning starting switch ON.
Wiring harnesses between EC1 (female)
(44) – BOOST PRESS & IMT (female) (1),
EC1 (female) (47) – BOOST PRESS & IMT
(female) (4).
Connecting parts among boost pressure sensor/temperature sen-
sor, engine wiring harness, and engine controller are suspected.
Inspect them directly.
• Loose connector, broken lock and, 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 (37) and
(47)
Voltage 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