Hino 238, Workshop Manual

Page: 654 / 919

DEF SCR SYSTEM (DCU) 5–88
DTC: P142B
EN01H16F02040F03001023
DTC: P142B DEF pump temperature sensor 1 - rationality
INFORMATION
1. Technical description
• DEF pump temperature sensor checks for validity by comparing with the outside temperature.
•
DEF pump temperature sensor checks for validity by monitoring whether the temperature rises when the coolant
shutoff valve is released (when DEF defrosts).
•
While the engine is cold, engine coolant will be sent to the pump to defrost the DEF.
<Description of malfunction>
•
Failure of temperature sensor inside DEF pump is detected.
2. DTC set condition
(1) DTC detection condition
When the starter switch is ON, difference among the outside temperature, exhaust temperature (SCR inlet) and cool-
ant temperature is within 8

C {46.4

F}.
The coolant shutoff valve is released (DEF defrosts). Coolant temperature is over 40

C {104

F}.
The above condition continues for 10 minutes or longer.
(2) Judgement criteria
Difference between the DEF pump temperature and the outside temperature: over 22

C {71.6

F}
Rise in the DEF pump temperature: less than 1.5

C {34.7

F}
ECU
Engine coolant
temperature sensor 1
#AW
#AV
#AW
#AV
#S5
#S7
#S5
#S7
LCM
H
L
(CA1H)
LCN
LF5
LF6
(CA1L) (CAL1)
KTU
KTD
E23
E24
E23
(WTM-)
(WTM+)
(AGD5)
(THW+)
K0U
KTD
KOU
H
L
(CAH1)
&RE
(CA2H)
&RJ
(CA2L)
&RD
(CA2H)
&RH
(CA2L)
LE4
LE5
LFG
LFH
(FAT-)
(FAT+)
LGJ
LGK
LNM
LNN
(HH1-)
(HH1+)
(ATS-)
(ATSS+)
(EXT-)
(EXT+)
(ER+)
(ER-)
LQ
U
LQV
Supply
module
(DEF
pump)
DCU
LFQ
(PSR+)
LFR
LGD
(PSRS)
(PSR+)
(PSRS)
LFP LGF
(PSR-)
(PSR-)
LFJ
(PMP+)
LFL
LG8
(PMPS)
(PMP+)
(PMPS)
LFK AGL
(PMP-)
(PMP-)
LFM BGL
(PMV+)
(PMV+)
LFN CGL
(PMV-)
(PMV-)
LGE
LG9
Ambient air
temperature
sensor
External
resistance
Exhaust gas
temperature
sensor
(SCR inlet)
Common rail_
CAN_J/C2
SAPH16F020400060