P0234: Overboost; Dtc: P0234 - Hino Motors HINO 155 series Workshop Manual

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DTC: P0234

P0234: Overboost

INFORMATION
Common rail
pressure sensor
Body earth
1. Technical description
• The VNT actuator moves the nozzle vane steplessly by the LEA (Linear Electric Actuator) to control the turbo speed
and boost pressure. It observes a deviation between the target boost pressure and actual boost pressure to check
if the actual pressure is higher than the target pressure.
<Description of malfunction>
• Boost pressure is higher than the stipulated value.
2. DTC set condition
(1) DTC detection condition
• Water temperature at engine start-up is 0 C {32 F} or more.
• The condition that the intake air temperature at engine start-up is less than 0 C {32 F} remains for 500 sec-
onds or more.
• The condition that the intake air temperature at the engine start-up is higher than 0 C {32 F} remains in the
range of 30 to 200 seconds.
The conditions described below remain for 4 seconds or more.
• The target boost pressure is 40 kPa (gauge) or more.
• If the engine speed is 750 r/min, fuel injection quantity is 100 mm
• If the engine speed is in range of 1250 to 1750 r/min, fuel injection quantity is 60 mm
• If the engine speed is 2500 r/min, fuel injection quantity is 120mm
• Atmospheric pressure is higher than 75 kPa.
• DPR auto-regeneration is inactive.
ENGINE (J05E)/TROUBLESHOOTING
Engine ECU
Boost pressure
sensor
Intake air
temperature sensor
(air flow sensor built in)
Actuator power
VNT EGR
controller actuator
Y2E
NAT
3
/st. cyl or more.
3
/st.cyl or more.
3
/st.cyl or more.
EN01H02127030602016062
Resistor
relay
Y4J Z90
X36 $4
SHTS021270300338