Hino 238, Workshop Manual

Page: 918 / 919

DEF SCR SYSTEM (DCU) 5–352
9
Inspect the
engine cool-
ant tempera-
ture sensor
1. Check the installation of the
engine coolant temperature
sensor.
2. Make sure there is no dirt or
damage to the engine cool-
ant temperature sensor.
Failure found:
Go to YES.
No failure
found: Go to
NO.
Clean the
engine cool-
ant tempera-
ture sensor
and install it
properly.
If damaged,
replace the
engine cool-
ant tempera-
ture sensor.
Perform "After-
inspection
work" of
INFORMA-
TION section.
Go to step 10.
10
Inspect the
engine cool-
ant tempera-
ture sensor
unit
Measure the resistance between
the terminals of the engine cool-
ant temperature sensor.
<Tester connections>
Engine coolant temperature sen-
sor
WTM+
–
WTM-
<Standard values>
20

C {68

F}: 2.59
–
2.32 k

80

C {176°F}: 0.326
–
0.310 k

The measure-
ments meet
the standard
value: Go to
YES.
The measure-
ments do not
meet the stan-
dard value: Go
to NO.
Go to step 11.
Replace the
engine cool-
ant tempera-
ture sensor.
Perform "After-
inspection
work" of
INFORMA-
TION section.
11
Check the
NOx sensor 2
[Hino-DX}
1. Replace the NOx sensor 2
with a new and erase the
malfunction history in Hino-
DX.
2. After DPR forced regenera-
tion, check if P2222 is
detected in the [DCU].
DTC P2222
has been
detected: Go
to YES.
No DTC has
been detected:
Go to NO.
Replace the
DCU. (After
replacing,
operate DPR
forced regen-
eration)
Perform "After-
inspection
work" of
INFORMA-
TION section.
Procedure
completed.
Perform "After-
inspection
work" of
INFORMA-
TION section.
DTC: P2222
NOx sensor (SCR downstream)
- Heater performance
Inspection Procedure
Step Action Description Judgement
Check
(Yes/No)
Yes No