Hino 238, Workshop Manual

Page: 154 / 919

ENGINE CONTROL SYSTEM (J08E) 4–931
DTC: P207F
EN01H16F01030F03001121
P207F: Improper reductant
INFORMATION
1. Technical description
•
Judge deterioration of DEF by observing a drop in purification efficiency.
• Use the NOx sensors installed in the upstream and downstream of the SCR catalyst to calculate purification effi-
ciency.
• Besides other factors, purification efficiency may drop due to the increase or decrease of DEF amount supplied to the
sensing unit.
<Description of malfunction>
• Poor DEF solution quality is detected.
2. DTC set condition
(1) DTC detection condition
Conditions below continues 60 seconds
500 kg/h
≤
Exhaust gas flow
<
1,000 kg/h
280

C {536

F}
≤
SCR catalyst temperature.
<
320

C {608

F}
0ppm
≤
NOx concentration (upstream.)
<
200 ppm
(NOx (SCR upstream.) stable, and NOx (SCR downstream.) stable)
Burner deactivated
(2) Judgement criteria
1. Calculate Average NOx conversion efficiency from NOx sensor (upstream.) and (downstream.) and Exhaust gas
mass flow
• Target NOx conversion efficiency (from DCU)
–
Average NOx conversion efficiency
≥
0.457
Supply module
(DEF pump)
Air flow
sensor
DEF
sensor
Exhaust gas
temperature
sensor (SCR inlet)
LFQ
(PSR+)
LFR
LGD
(PSRS)
(PSR+)
(PSRS)
LFP LGF
(PSR-)
(PSR-)
LFJ
(PMP+)
LFL
LG8
(PMPS)
(PMP+)
(PMPS)
LFM LGB
(PMV+)
(PMV+)
LFN LGC
(PMV-)
(PMV-)
LFK LGA
(PMP-)
(PMP-)
LGE
LG9
LE4
LE5
LFG
LFH
(FAT-)
(FAT+)
(EXT-)
(EXT+)
NOx
sensor 1
NOx
sensor 2
%JU
%JZ
%JQ
%KF
%JV
(CA2H)
(CA2L)
(CA2H)
(CA2L)
(CA3H)
%KH
%KG
(CA3L)
(CA3H)
%KE
(CA3L)
%KM
(CA3H)
%KL
(CA3L)
%JR
(CA2H)
%JW
(CA2L)
LE9
LE8
(CANH) (CANL)
H
L
H
L
H
L
H
L
%JS
(CA2H)
%JX
(CA2L)
LED
LEC
(CANH)
(CANL)
KTT K0W KTT (AFT+)
(THA+)
K0W
KTR
KTQ
L2P
LCH
KTS
KTR
KTQ
KTS
(AFGD)
(AFSG)
(AFVB)
(AGD6)
(AFSI)
(AFVB)
L75
L2P
LCH
KTU KTD KTU (AFT-)
(AGD5)
KTD
L75
Engine
ECU
DCU
#S5
#S7
#S5
#S7
#AW
#AV
#AW
#AV
LCM
H
L
(CA1H)
LCN
LF5
LF6
(CA1L) (CAL1)
#CP #CP
#CQ #CQ
#SD #SD
#SF #SF
K6V (CANH)
K6W
(CANL)
H
L
&RE
(CA2H)
&RJ
(CA2L)
&RD
(CA2H)
%KC
(CA2L)
(CAH1)
LEY
LEZ
250K
500K
(CAL0)
(CAH0)
LJM LJN
(CAH1) (CAL1)
LJK
LJL
(CAH0)
(CAL0)
&RF
&RK
(CA2H)
(CA2L)
LEK
LEJ
(CANL)
(CANH)
%KP
%KN
(CA3H)
(CA3L)
BCU
SAPH16F010300727