Failure Code [Ca221] Ambient Press Sens High Error - Komatsu PC200-8M0 Shop Manual

SEN06133-00

Failure code [CA221] Ambient Press Sens High Error

Action
Failure code
level
L03 CA221
q
Detail of failure High voltage appears in signal circuit of ambient pressure sensor.
Action of con-
q
Takes ambient pressure to be at fixed value and allows engine to run.
troller
q
Problem on Engine output lowers.
machine q Engine starting performance becomes deteriorated.
q
Input voltage from ambient pressure sensor can be checked with monitoring function.
(Code: 37401 (V))
Related infor-
q
Ambient pressure sensed by ambient pressure sensor can be checked with monitoring function.
mation
(Code: 37400 (kPa))
q
Method of reproducing failure code: Turn starting switch to ON position.
Cause
Defective wiring harness connec-
1
tor
Defective sensor power supply 1
2
system
3 Defective ambient pressure sensor
4 Short circuit in wiring harness
Hot short circuit in wiring harness
5
(Contact with 24 V circuit)
6 Defective engine controller
40
40-301
Ambient Pressure Sensor High Error
Failure
(Engine controller system)
Procedure, measuring location, criteria and remarks
See descriptions of wiring harness and connectors in "c: Electrical equipment"
in "Checks before troubleshooting" of "General information on troubleshoot-
ing", and check them.
If failure code [CA352] or [CA386] is displayed simultaneously, perform trou-
bleshooting for it first.
1. Turn starting switch to OFF position.
2. Disconnect connector AMB. AIR PRESSURE.
3. Turn starting switch to ON position.
If failure code changes from [CA221] to [CA222], sensor is defective.
q
Reference
1. Turn starting switch to OFF position.
2. Insert T-adapters to connector ECM.
3. Turn starting switch to ON position.
Between ECM (3) and (38)
1. Turn starting switch to OFF position.
2. Disconnect connectors ECM and AMB. AIR PRESSURE, and connect
T-adapters to either female side.
Between ECM (female) (33) and (3), or between
AMB. AIR PRESSURE (female) (1) and (3)
1. Turn starting switch to OFF position.
2. Disconnect connector AMB. AIR PRESSURE.
3. Connect T-adapter to female side of connector AMB. AIR PRESSURE or
insert T-adapter in connector ECM.
4. Turn starting switch to ON position (with connector AMB. AIR PRESSURE
disconnected).
Between ECM (3) and (38), or between AMB. AIR
PRESSURE (female) (3) and (2)
If no failure is found by above checks, engine controller is defective. (Since
this is an internal defect, troubleshooting cannot be performed.)
301 Troubleshooting by failure code, Part 1

Failure code [CA221] Ambient Press Sens High Error

Sensor out-
put
PC200, 200LC, 220, 220LC-8M0
Voltage 0.5 to 4.5 V
Resistance Min. 100 kz
Voltage Max. 1 V