ENGINE CONTROL SYSTEM (J08E)
4–873
CHECKLIST: P14B3 and P14B4
DTC: P14B3
Battery voltage (high)
(EGR actuator power supply too high)
Inspection procedure
DTC: P14B4
Battery voltage (low)
(EGR actuator power supply too low)
Step
Action
Description
Judgement
Check
(Yes/No)
Yes
No
1
Check the
DTC detected
1 (Engine
ECU) [Hino-
DX]
Check if any DTC other than DTC
(P14B3 or P14B4) has been
detected in [Engine].
DTC other
than DTC
(P14B3 or
P14B4) has
been detected:
Go to YES.
No DTC has
been detected.
Go to NO.
Go to diagno-
sis procedure
of a related
DTC.
Go to step 2.
2
Inspect the
EGR valve
connector
Check the connection of the EGR
valve connector (Looseness and
poor contact).
Failure found:
Go to YES.
No failure
found: Go to
NO.
Connect
securely,
repair if
needed.
Perform "After-
inspection
work" of
INFORMA-
TION section.
Go to step 3.
3
Inspect the
EGR valve
power supply
Disconnect the EGR valve con-
nector and measure the voltage
between the terminals of the EGR
valve vehicle-side connector.
<Tester connections>
EGR valve vehicle-side connector
EGRV
–
EGRG
<Standard values>
8
–
16 V
The measure-
ments meet
the standard
value: Go to
YES.
The measure-
ments do not
meet the stan-
dard value: Go
to NO.
Replace the
EGR valve,
and go to step
4.
Check the wire
harness (actu-
ator power
supply and
ground).
Repair or
replace parts
as needed.
Perform "After-
inspection
work" of
INFORMA-
TION section.
4
Check the
DTC detected
2 (Engine
ECU) [Hino-
DX]
Check if the DTC (P14B3 or
P14B4) has been detected in
[Engine].
DTC (P14B3
or P14B4) has
been detected:
Go to YES.
No DTC has
been detected:
Go to NO.
Replace the
engine ECU.
Perform "After-
inspection
work" of
INFORMA-
TION section.
Procedure
completed.
Perform "After-
inspection
work" of
INFORMA-
TION section.
Summary of Contents for 238
Page 201: ...ENGINE CONTROL SYSTEM J08E 4 978 Harness disconnection or short circuit ...
Page 215: ...ENGINE CONTROL SYSTEM J08E 4 992 Malfunction of sensor 2 Malfunction of engine ECU ...
Page 301: ...ENGINE CONTROL SYSTEM J08E 4 1078 8 Estimated failure factors Malfunction of engine ECU ...
Page 709: ...DEF SCR SYSTEM DCU 5 143 8 Estimated failure factors DEF pump pressure sensor malfunction ...