
DIESEL FUEL <4D5-stepIII>-Troubleshooting13E-10
Code No. 12 Boost pressure sensor (boost sensor)
systemProbable cause
Range of Check
DIgnition switch: ON, except for during engine cranking
Set Conditions
DSensor output voltage for 1 second is 4.5 V or higher
(boost pressure is approximately 267 kPa).
or
DSensor output voltage for 1 second is 0.2 V or lower
(boost pressure is approximately 51.7 kPa or lower)
Range of Check
DEngine speed is 2,000 r/min or higher, barometric pressure is 69.7 kPa or
less (equivalent to an altitude of 300 m) and under high load.
Set Conditions
DBoost pressure is lower than the barometric pressure + 13 kPa for 3
seconds.DBoost pressure sensor inoperative
DBoost pressure sensor open circuit, short circuit,
or connector contact inoperative
DBoost pressure sensor hose disconnected
DEngine-ECU inoperative
NG
Check the trouble symptoms.
Replace the engine-ECU.
Check the following connector:
D-113
NGOK
NG
Repair
RepairOK
NG
Check the trouble symptoms.
OKOK
OK
Check the following connector:
B-08NG
Check the trouble symptoms. NG
Repair
NG
NG
Check the vacuum hose between the
boost pressure sensor and the intake
manifold.
Replace the boost pressure sensor.
OK OK OK
Repair
NG
Repair
Check the trouble symptoms.
Check the harness between the
engine-ECU and the boost pressure
sensor connector, and repair if
necessary.
NG OK
NG
RepairCheck the following connector:
B-08NG
Measure at B-08 boost pressure
sensor connector
DConnect the connector.
(Test harness: MB991348 used)
DVoltage between 1 and the earth
(Engine: Idling)
OK:1.3 - 1.7 V
DVoltage between 1 and the earth
OK:When the accelerator pedal
is suddenly pressed from
the idling condition, the
voltage temporarily in-
creases from 1.3 V to 1.7
V.
Measure at D-113 engine-ECU
connector
DConnect the connector.
DVoltage between 85 and the
earth (Engine: Idling)
OK:1.3 - 1.7 V
Check the harness between the
engine-ECU and the boost pressure
sensor connector.
Measure at B-08 boost pressure
sensor connector
DDisconnect the connector and
measure at the harness side.
DVoltage between 3 and the earth
(Ignition switch: ON)
OK:4.5 - 5.5 V
DContinuity between 2 and the
earth
OK:Continuity
Replace the engine-ECU.NGCheck the harness between the
engine-ECU and the boost pressure
sensor connector.
Replace the engine-ECU.OK
NG
Repair
Check the following connector:
D-112
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15-1
INTAKE AND
EXHAUST
CONTENTS
SERVICE SPECIFICATIONS 2.................
SEALANT 2..................................
SPECIAL TOOL 2............................
ON-VEHICLE SERVICE 2.....................
Intake Manifold Vacuum Check <6G7> 2.........
Turbocharger Supercharging Check <4D5> 2.....
Waste Gate Actuator Check <4D5> 3..........
Waste Gate Actuator Check <4M4> 3..........
AIR CLEANER 4.............................
INTERCOOLER<4D5, 4M4> 5.................
INTAKE MANIFOLD <6G7> 6.................
INTAKE MANIFOLD AND THROTTLE BODY
<4M4> 8.....................................EXHAUST MANIFOLD <6G7> 11..............
INTAKE MANIFOLD AND EXHAUST
MANIFOLD, TURBOCHARGER <4D5> 12...
TURBOCHARGER AND EXHAUST
MANIFOLD <4M4> 14.....................
TURBOCHARGER <4D5> 16.................
TURBOCHARGER <4M4> 19.................
EXHAUST PIPE AND MAIN MUFFLER
<6G7> 21...................................
EXHAUST PIPE AND MAIN MUFFLER
<4D5> 23...................................
EXHAUST PIPE AND MAIN MUFFLER
<4M4> 25...................................
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INTAKE AND EXHAUST -Intake and Exhaust Manifold,
Turbocharger <4D5>15-13
INSTALLATION SERVICE POINT
"
AA
TURBOCHARGER ASSEMBLY INSTALLATION
1. Check the internal surface, the eye bolt and the
mating surface of the oil pipe and water pipe for
clogging, and clean if necessary.
2. If deposits of carbon are accumulated on the
turbocharger oil passage, remove them and clean
using the compressed air.
Caution
Be careful not to allow foreign material to enter the
turbocharger.
3. Add clean engine oil through the oil feed pipe port
on the turbocharger.
INSPECTION
TURBOCHARGER ASSEMBLY CHECK
DVisually check the turbine wheel and the compressor
wheel for cracking or other damage.
DCheck whether the turbine wheel and the compressor
wheel can be easily turned by hand.
DCheck for oil leakage from the turbocharger assembly.
DCheck whether or not the waste gate valve remains open.
If any problem is found, replace the part after disassembly.
OIL PIPE AND OIL RETURN PIPE CHECK
Check the oil pipe and oil return pipe for clogging, bending,
or other damage. If there is clogging, clean it.
EXHAUST MANIFOLD CHECK
Damage or cracking of any part.
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INTAKE AND EXHAUST -Turbocharger and Exhaust
Manifold <4M4>15-15
INSTALLATION SERVICE POINT
"
AA
TURBOCHARGER ASSEMBLY INSTALLATION
1. Check the internal surface, the eye bolt and the
mating surface of the oil pipe and water pipe for
clogging, and clean if necessary.
2. If deposits of carbon are accumulated on the
turbocharger oil passage, remove them and clean
using the compressed air.
Caution
Be careful not to allow foreign material to enter the
turbocharger.
3. Add clean engine oil through the oil feed pipe port
on the turbocharger.
INSPECTION
Check the following points; replace the part if a problem is
found.
EXHAUST MANIFOLD CHECK
1. Check for damage or cracking of any part.
2. Using a straight edge and a thickness gauge, check for
distortion of the cylinder head installation surface.
Standard value: 0.15 mm or less
Limit: 0.20 mm
TURBOCHARGER ASSEMBLY CHECK
DVisually check the turbine wheel and the compressor
wheel for cracking or other damage.
DCheck whether the turbine wheel and the compressor
wheel can be easily turned by hand.
DCheck for oil leakage from the turbocharger assembly.
DCheck whether or not the waste gate valve remains open.
If any problem is found, replace the part after disassembly.
OIL PIPE AND OIL RETURN PIPE CHECK
Check the oil pipe and oil return pipe for clogging, bending,
or other damage. If there is clogging, clean it.
EXHAUST MANIFOLD CHECK
Damage or cracking of any part.
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15-1
INTAKE AND
EXHAUST
CONTENTS
GENERAL 2.................................
Outline of Changes 2...........................
GENERAL INFORMATION 2..................
SERVICE SPECIFICATIONS 3.................
SEALANT 3..................................
ON-VEHICLE SERVICE 4.....................
Turbocharger Supercharging Check 4............
Supercharging Pressure Control
System Check 5...............................
Variable Geometry Actuator Check 6.............Variable Geometry Solenoid Valve Check 6.......
INTAKE MANIFOLD AND THROTTLE BODY
<4M4> 7.....................................
INTAKE MANIFOLD AND EXHAUST
MANIFOLD, THROTTLE BODY AND
TURBOCHARGER <4D5> 10..................
TURBOCHARGER AND EXHAUST
MANIFOLD <4M4> 12........................
EXHAUST PIPE AND MAIN MUFFLER
<4D5> 14....................................
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INTAKE AND EXHAUST -General Information/Service Specifications/Sealant15-3
At starting and driving at low speed, the duty control
value of the variable geometry solenoid valve is
increased to apply the vacuum pressure of the
vacuum pump to the variable geometry actuator.
Applying the vacuum pressure to the variable
geometry actuator pulls the actuator rod so that
it can move towards the direction of closing the
variable nozzle of the variable geometry
turbocharger. As closing the nozzle reduces the
exhaust gas mass, the speed of exhaust gas flow
will be increased and efficiency will be improved.
Since the characteristic of boost pressure becomes
a low speed type, boost pressure will suddenly
rise from low speed.
At driving at high speed, the duty control value
of the variable geometry solenoid valve is
decreased to reduce the vacuum pressure from
the vacuum pump so that the actuator rod can
return to the deactivated status and move towards
the direction of opening the nozzle of the variable
geometry turbocharger.Opening the nozzle allows the characteristic of
boost pressure to become a high speed type so
that the appropriate boost pressure can be
maintained.
Therefore, boost pressure can be controlled by
appropriate duty control of the variable geometry
solenoid valve. The engine-ECU calculates the
correct boost pressure based on the engine speed
and fuel injection amount. Furthermore, the duty
control of the variable geometry solenoid valve is
given feedback of the signals from the variable
geometry control pressure sensor and the boost
pressure sensor so that the variable nozzle opening
angle of the variable geometry turbocharger can
be quickly adjusted to obtain the desired boost
pressure.
SERVICE SPECIFICATIONS
ItemsStandard value
Variable geometry actuator activation vacuum
(Approximately 1 mm stroke) kPaApproximately 10.5 - 12.5
Variable geometry solenoid valve coil resistance
(at 20°C)Ω29 - 35
SEALANT
ItemSpecified sealantRemarks
Thread of the intake manifold mounting
bolts3M Stud Locking No.4170 or equivalentAnaerobic sealant
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INTAKE AND EXHAUST -Turbocharger and Exhaust
Manifold <4M4>15-13
INSTALLATION SERVICE POINT
"AATURBOCHARGER ASSEMBLY INSTALLATION
1. Check the internal surface, the eye bolt and the
mating surface of the oil pipe and water pipe for
clogging, and clean if necessary.
2. If deposits of carbon are accumulated on the
turbocharger oil passage, remove them and clean
using the compressed air.
Caution
Be careful not to allow foreign material to enter the
turbocharger.
3. Add clean engine oil through the oil feed pipe port
on the turbocharger.
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