Failure Code [Ca689] Eng Ne Speed Sensor Error - Komatsu PC200-8M0 Shop Manual

SEN06134-00

Failure code [CA689] Eng Ne Speed Sensor Error

Action
Failure code
level
L01 CA689
q
Detail of failure Signal from engine Ne speed sensor is abnormal.
Action of con-
q
Continues to control engine by using signal from engine Bkup speed sensor.
troller
q
Engine hunts.
Problem on
q Starting performance is poor.
machine
q
Engine output lowers.
q
Method of reproducing failure code: Start engine.
q
Since inside of speed sensor is not composed of coil but Hall sensor and electronic circuit, speed
sensor cannot be determined to be normal by measuring its resistance with multimeter.
Related infor-
q
Since speed sensor output is 5 V pulse voltage during normal operation, it cannot be measured by
mation
using multimeter.
q
Speed sensor senses passing slotted hole in speed sensing wheel that is installed on inside of
crankshaft vibration damper and rotated by crankshaft.
Cause
Defective wiring harness connec-
1
tor
Defective Ne speed sensor power
2
supply system
Breakage or improper installation
3 (looseness) of engine Ne speed
sensor
Defective Ne speed sensor power
4
supply input
Open circuit in wiring harness
5 (wire breakage or defective con-
tact of connector)
6 Short circuit in wiring harness
Ground fault in wiring harness
7
(contact with ground circuit)
40
40-302
Engine Ne Speed Sensor 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 [CA238] is also displayed, perform troubleshooting for it first.
Engine Ne speed sensor may be broken or may have improper installation
(looseness). Check it directly.
1. Turn starting switch to OFF position.
2. Disconnect connector CRANK SENSOR and connect T-adapter to female
side.
3. Turn starting switch to ON position.
Between CRANK SENSOR (female)
(1) and (2)
1. Turn starting switch to OFF position.
2. Disconnect connectors ECM and CRANK SENSOR.
a If no failure is found in checks on cause 4, this
check is not required.
Between ECM (female) (16) and CRANK
SENSOR (female) (1)
a If no failure is found in checks on cause 4, this
check is not required.
Between ECM (female) (48) and CRANK
SENSOR (female) (2)
Between ECM (female) (27) and CRANK SENSOR
(female) (3)
1. Turn starting switch to OFF position.
2. Disconnect connectors ECM and CRANK SENSOR.
Between ECM (female) (16) and (27) or CRANK
SENSOR (female) (1) and (3)
Between ECM (female) (27) and (48) or CRANK
SENSOR (female) (2) and (3)
1. Turn starting switch to OFF position.
2. Disconnect connectors ECM and CRANK SENSOR.
Between ECM (female) (27) or CRANK SENSOR
(female) (3) and ground
302 Troubleshooting by failure code, Part 2

Failure code [CA689] Eng Ne Speed Sensor Error

Power sup-
Voltage
ply input
Resis-
tance
Resis-
tance
Resis-
tance
Resis-
tance
Resis-
tance
Resis-
tance
PC200, 200LC, 220, 220LC-8M0
4.75 to 5.25V
Max. 10 z
Max. 10 z
Max. 10 z
Min. 100 kz
Min. 100 kz
Min. 100 kz