Failure Code [Ca221] Ambient Pressure Sensor High Error - Komatsu PC88MR-10 Shop Manual

Failure code [CA221] Ambient Pressure Sensor High Error

A)
Action level Failure code
L03 CA221
Detail of
High voltage occurs in signal circuit of ambient pressure sensor.
failure
Sets ambient pressure to fixed value (52.44 kPa {0.53 kg/cm
Action of
Closes EGR valve and opens variable flow turbocharger fully.
controller
Limits engine output and runs engine.
Problem on
Engine output lowers.
machine
Signal voltage from ambient pressure sensor can be checked with monitoring function.
(Code: 37401 (V))
Related
Ambient pressure sensed by ambient pressure sensor can be checked with monitoring
information
function. (Code: 37400 (kPa))
Method of reproducing failure code: Turn starting switch to ON position.
No. Cause
Defective wiring
1
harness connector
Defective ambient
pressure sensor power
2
supply system
Defective ambient
3
pressure sensor
Open circuit in wiring
harness
4
(wire breakage or
defective contact of
connector)
Short circuit in wiring
5
harness
Hot short circuit in
6
wiring harness
Defective engine
7
controller
PC88MR-10
Ambient Pressure Sensor High Error
Failure
(Engine controller system)
Procedure, measuring location, criteria, and remarks
1. See descriptions of wiring harness and connectors in "c: Electrical
equipment" in "Checks before troubleshooting" of "Related information on
troubleshooting", and check it.
2. Turn starting switch to ON position.
If this failure code is not displayed, wiring harness connector is defective.
a If this failure code is displayed, perform following checks.
If failure code [CA187] or [CA227] is also displayed, perform troubleshooting
for it first.
1. Turn starting switch to OFF position.
2. Disconnect connector PAMB.
3. Turn starting switch to ON position.
If failure code changes from [CA221] to [CA222], sensor is defective.
Reference
1. Turn starting switch to OFF position.
2. Insert T-adapters into connector J1 or PAMB.
3. Turn starting switch to ON position.
Between J1 (16) and (59), or between
Voltage
PAMB (3) and (2)
1. Turn starting switch to OFF position.
2. Disconnect connectors J1 and PAMB, and connect T-adapters to each
female side.
a To check open circuit in GND line
Resistance Between J1 (female) (59) and PAMB (female) (2)
1. Turn starting switch to OFF position.
2. Disconnect connectors J1 and PAMB, and connect T-adapter to either
female side.
Between J1 (female) (60) and (16), or between
Resistance
PAMB (female) (1) and (3)
1. Turn starting switch to OFF position.
2. Disconnect connector PAMB, and connect T-adapter to female side.
3. Turn starting switch to ON position.
Voltage Between PAMB (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.)
40 Troubleshooting
Troubleshooting by failure code (Display of code)
2 }) and runs engine.
(PC88MR-CA221-400-A-Z0-
Sensor
0.3 to 4.7 V
output
Max. 1 z
Min. 1 Mz
Max. 1 V
40-147