When Starting Switch Is Turned To On Position, Machine Monitor Displays Nothing - Komatsu PC88MR-10 Shop Manual

E-4 When starting switch is turned to ON position, machine monitor
displays nothing

When starting switch is turned to ON position, machine monitor displays nothing.

Failure
When starting switch is turned to ON position, machine monitor displays KOMATSU logo,
password input screen (if set), operator ID input screen (if set), check-before-starting
screen, check working mode screen, check travel speed screen, and standard screen in
Related
order.
information
Depending on ambient temperature and condition of battery, battery voltage may lower
suddenly and machine monitor displays nothing temporarily when engine is started. But
this phenomenon does not mean that machine monitor is defective.
No. Cause
Battery disconnect
switch left in OFF
1
position
Insufficient battery
2
capacity
Defective fusible link
3
F03
4 Defective fuse F01-15
5 Defective fuse F01-17
Loose terminal or open
6
circuit at terminal
Defective wiring
7 harness, starting switch,
or machine monitor
Defective starting
switch
8
(Internal open circuit)
Open circuit in wiring
harness
9
(Internal open circuit)
PC88MR-10
(PC88MR-FEG-400-A-Z0-A)
Procedure, measuring location, criteria, and remarks
Turn starting switch to OFF position and check that battery disconnect switch
is in ON position.
a Be ready with starting switch at OFF position, then perform
troubleshooting without turning starting switch to ON position.
Battery voltage (2 batteries)
Specific gravity of electrolyte (each
battery)
If fusible link is burnt out, circuit probably has ground fault. (See Cause 9.)
If fuse is burnt out, circuit probably has ground fault. (See Cause 10.)
If fuse is burnt out, circuit probably has ground fault. (See Cause 10.)
1. Turn starting switch to OFF position.
Check terminals of battery relay, etc.
1. Turn starting switch to OFF position.
2. Turn battery disconnect switch to OFF position.
3. Insert T-adapter into connector CM01.
4. Turn battery disconnect switch to ON position.
5. Turn starting switch to ON position (to connect ACC).
Between CM01 (1) and (3)
Voltage Between CM01 (2) and (4)
Between CM01 (10) and (4)
1. Turn starting switch to OFF position.
2. Disconnect connector H15 and connect T-adapter to male side.
3. Turn starting switch to ON position and perform troubleshooting again.
Between H15 (male) (1)
and (5)
Resistance
Between H15 (male) (1)
and (5)
If no failure is found by check on Cause 7, this check is not required.
1. Turn starting switch to OFF position.
2. Turn battery disconnect switch to OFF position.
3. Disconnect fusible link F03, No. 15 and 17 fuses of fusebox F01, and
connectors H15 and CM01.
4. Connect T-adapters to male side of connector F03 and female side of H15
and CM01.
Between battery (-) terminal and ground
Between battery (+) and F03 (male) (1)
Between F03 (male) (2) and F01-16F
Between F01-17 and CM01 (female) (1), (2)
Resistance Between ground (T09) and each of CM01 (female)
(3) and (4)
Between F01-17 and H15 (female) (1)
Between H15 (female) (5) and F01-15E
Between F01-15 and CM01 (female) (10)
40 Troubleshooting
Troubleshooting of electrical system (E-mode)
Min. 24 V
Min. 1.26
Turn starting switch to
OFF position.
Turn starting switch to
ON position.
20 to 30 V
20 to 30 V
20 to 30 V
Min. 1 Mz
Max. 1 z
Max. 1 z
Max. 1 z
Max. 1 z
Max. 1 z
Max. 1 z
Max. 1 z
Max. 1 z
Max. 1 z
40-389