Failure Code [Ca187] Sensor 2 Supply Voltage Low Error - Komatsu PC88MR-10 Shop Manual

Failure code [CA187] Sensor 2 Supply Voltage Low Error

Action level Failure code
L03 CA187
Detail of
Low voltage occurs in sensor power supply 2 (5 V) circuit.
failure
Ignores signals from Bkup speed sensor and controls engine by using Ne speed sensor
signals.
Ignores signals from engine oil pressure sensor, sets engine oil pressure to fixed value
(250 kPa {2.5 kg/cm
Ignores signals from ambient pressure sensor, sets ambient pressure to fixed value
(52.44 kPa {0.53 kg/cm
Action of
Ignores signals from charge (boost) pressure sensor, sets boost pressure to fixed value
controller
(400 kPa {4.1 kg/cm
Ignores signals from crankcase pressure sensor, sets crankcase pressure to fixed value
(0 kPa), and runs engine.
Closes EGR valve and opens variable flow turbocharger fully.
Limits engine output and runs engine.
Problem on
Engine output lowers.
machine
Related
Method of reproducing failure code: Turn starting switch to ON position.
information
No. Cause
Defective wiring
1
harness connector
Defective sensor or
2
wiring harness
Defective relevant
3
system
Defective engine
4
controller
PC88MR-10
Sensor 2 Supply Voltage Low Error
Failure
(Engine controller system)
2 }), and runs engine.
2 }), and runs engine.
2 }), and runs engine.
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.
1. Turn starting switch to OFF position.
2. Disconnect following connectors one by one and turn starting switch to ON
position each time.
3. Each time troubleshooting is finished, return to step 1.
If this failure code is not displayed, disconnected sensor or engine wiring
harness is defective.
a Other failure codes (many codes) are also displayed. They are generated
because of disconnection of connector. Ignore failure codes other than
[CA187].
Bkup speed sensor
Charge (Boost) pressure sensor
Ambient pressure sensor
Connector
Crankcase pressure sensor
Engine harness
If other failure codes are also displayed, perform troubleshooting for them.
1. Turn starting switch to OFF position.
2. Disconnect connector J1 and connect T-adapter to male side.
3. Turn starting switch to ON position with connector J1 disconnected.
Voltage Between ECM J1 (male) (60) and (59)
40 Troubleshooting
Troubleshooting by failure code (Display of code)
(PC88MR-CA187-400-A-Z0-A)
CAM
TMAP
PAMB
CCV
J1
4.75 to 5.25
V
40-145