Preheater Does Not Operate - Komatsu Galeo PC138US-8 Shop Manual

SEN02467-00
E-4 Preheater does not operate
Trouble (1) When starting switch is turned to HEAT position, preheating monitor does not light up or flash.
• Preheater monitor lights up when starting switch is turned to HEAT and starts flashing about 30 sec-
onds after to notify completion of preheating (It stops flashing about 10 seconds after).
Related • If engine coolant temperature is below 20°C, automatic warm-up system operates and preheating
information monitor lights up for up to 30 seconds.
• Condition of starting switch (preheating) signal can be checked with the monitoring function.
(Code: 04500 Monitor input 1)
Defective starting switch
1
(Internal disconnection)
Possible causes
Disconnection in wiring har-
and standard
ness (Disconnection in wiring
value in normal
2
or defective contact in con-
state
nector)
3 Defective machine monitor
(2) When starting switch is turned to HEAT position, intake air heater mounting part does not become
Trouble
warm.
Related • Check that engine can be turned with starting motor (If engine cannot be turned, carry out trouble-
information shooting for E-1 Engine does not start (Engine does not turn)).
Defective heater relay (Inter-
1
nal disconnection)
Possible causes
and standard
value in normal
Defective intake air heater
state
2
(Internal disconnection)
Disconnection in wiring har-
ness (Disconnection in wiring
3
or defective contact in con-
nector)
12
Cause
a Prepare with starting switch OFF, then keep starting switch OFF
Between (1) – (3)
a Prepare with starting switch OFF, then carry out troubleshooting
Wiring harness between CM01 (female)
(16) – J04 – H15 (female) (3)
a Prepare with starting switch OFF, then keep starting switch OFF
Between (16) –
chassis ground
Cause Standard value in normal state/Remarks on troubleshooting
a Prepare with starting switch OFF (with wiring harness con-
Between R15 –
chassis ground
Between power
supply terminal –
a Prepare with starting switch OFF (with wiring harness con-
Between terminal –
chassis ground
If voltage is normal but heater mounting part does not become
warm, intake air heater is defective.
a Prepare with starting switch OFF, then carry out troubleshoot-
Wiring harness between H15 (female) (3) –
J04 – heater relay R15
Wiring harness between battery relay RM –
heater relay contact terminal (F04)
Wiring harness between heater relay R16 –
intake air heater E01
Standard value in normal state/Remarks on troubleshooting
and turn it to HEAT and carry out troubleshooting in each case.
H15 (female) Starting switch
without turning starting switch ON.
and turn it to HEAT and carry out troubleshooting in each case.
CM01 Starting switch
nected), then keep starting switch OFF and turn it to HEAT and
carry out troubleshooting in each case.
Heater relay Starting switch
R16
nected), then turn starting switch to HEAT and carry out trou-
bleshooting in each case.
E01 Starting switch
ing without turning starting switch ON.
40 Troubleshooting
Resistance
OFF Min. 1 Mz
Max. 1 z
HEAT
Resis-
tance
Voltage
OFF Max. 1 V
HEAT 20 – 30 V
Continuity/Resis-
tance
OFF There is continuity
Max. 1 z
HEAT
Voltage
HEAT 20 – 30 V
Resis-
tance
Resis-
tance
Resis-
tance
PC138US, USLC-8
1
Max. 1 z
Max. 1 z
Max. 1 z
Max. 1 z