Suzuki Grand Vitara JB419. Service manual — part 32

Engine General Information and Diagnosis: 1A-105

Test 2: Low pressure circuit check

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Step

Action

Yes

No

1

Check the fuel filter:
• Conformity of the fuel filter.
• Positioning and degree of contamination of the filter

cartridge.

• Positioning and condition of the seals.
• If there is metal swarf in the filter:

Replace the fuel filter, bleed the circuit and continue the
fault finding procedure.

Is there in good condition?

Go to Step 2.

Repair or replace the
defective part.

2

Supplying the injection system with fuel from an additional
tank.
This operation aims to detect possible faults in the low
pressure supply system of a vehicle by replacing it entirely
with an additional tank.
Mode:
• Disconnect the diesel fuel supply pipe at the fuel filter inlet

and seal it with a plug.

• Connect a pipe to the fuel filter inlet and insert the other

end in a clean container of approximately 5 liters.

• Disconnect the diesel fuel return pipe at the pump return

and injector leak-off junction and seal it with a plug.

• Fill the container with clean diesel fuel.
• Start the engine and let the system drain itself of its air

(there must not be any air bubbles in the return pipe).

Does the customer complaint persist?

If the low pressure
circuit is in order,
reconnect the different
pipes of the low
pressure circuit and
repeat the fault finding
of the fault finding chart
or of the fault that
referred you to this test.

Go to Step 3.

3

Are the low pressure circuit connections in order and in good
condition?

Go to Step 4.

Carry out the necessary
repairs.

4

Check the condition of the priming pump, and that it is
working properly. Perform repairs if necessary and continue
the test.

Is there in good condition?

Go to Step 5.

Repair or replace the
defective part.

5

If the fault is still present with a low fuel level, check the
consistency of the actual fuel level and that indicated on the
combination meter.
• The fuel pump is supplied via a venturi pipe located

underneath it.

Check that the opening of the venturi (6 to 8 mm (0.24 to
0.31 in.) in diameter) is not blocked by dirt contained in the
fuel tank. Check the priming of the low pressure diesel fuel
circuit.

Is there in good condition?

Go to Step 6.

Repair or replace the
defective part.

6

Ensure that the correct fuel is being used:
• Smell and compare the fuel with unpolluted diesel fuel:

to detect petrol, solvent, thinner, sulphuric acid (fuel with a
white colour), water or fuel oil.

If the diesel fuel is not correct:
• Replace the diesel fuel.
• Change the diesel filter.
• Bleed the low and high pressure diesel circuit.

Is there in good condition?

Low-pressure circuit
correct.

Repair or replace the
defective part.

1A-106 Engine General Information and Diagnosis:

Test 3: Checking the turbocharged air inlet circuit

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Step

Action

Yes

No

1

Engine stopped: Check the low and high pressure air circuits
for leaks (air leaks in or out, before and after the
turbocharger). Look for parts of the system that are
abnormally greasy, indicating leakage.
Check:
• The condition and fitting of the ducts (foreign bodies,

clogged, disconnected, pinched, broken, holed, cut,
tightness of the mounting bolts, etc.).

• The presence, condition and fitting of the seals.
• The presence and tightening of the clamps.
• The fitting of the boost pressure sensor.

Is there in good condition?

Go to Step 2.

Carry out the necessary
repairs.

2

Checking the air filter.
Check:
• The air filter unit inlet and outlet are not blocked.
• The condition and the assembly of the air filter unit

(disconnected, broken, with holes, etc.).

• The cleanliness, conformity and the non-distortion of the

filter element.

• The MAF sensor: apply test 4.

Is there in good condition?

Go to Step 3.

Carry out the necessary
repairs.

3

Checking the inlet throttle valve.
Check:
• The condition of the inlet throttle valve.
• The tightness of the mounting bolts.
• Cracks in the damper valve.

Is there in good condition?

Go to Step 4.

Carry out the necessary
repairs.

4

Check that there is no leak on the exhaust manifold, in
particular at the exhaust manifold/turbocharger interface.
Check the exhaust system: apply test 1 referring to “Test 1:
Exhaust system check”.

Is there in good condition?

Go to Step 5.

Carry out the necessary
repairs.

5

Check the condition of the intercooler:
• Clogging,
• Leaks (vehicle stationary, stabilise the engine speed

between 3500 rpm and 4000 rpm and check that there
are no leaks).

Air inlet circuit correct.

Replace the intercooler.

Engine General Information and Diagnosis: 1A-107

Test 4: MAF sensor

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Test 5: Variable geometry turbocharger control

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Step

Action

Yes

No

1

BREAKAGE OF ELECTRICAL COMPONENTS:
Visual inspection: remove the MAF sensor assembly with
IAT sensor, the components must not be broken

Is there in good condition?

Go to Step 2.

Replace the MAF
sensor assembly with
IAT sensor if necessary.

2

CLOGGING OF THE MAF SENSOR:
Test:
• Check the values for conformity:

– * During the first 5 seconds after starting:

– Coolant temperature: 80

°C, 176 °F.

– Engine speed: idle speed (800

± 50 rpm).

– MAF measurement: 490 mg/str

± 10%.

– EGR valve: between –10% and 0%.

– * After the starting phase:

– Coolant temperature: 80

°C, 176 °F.

– Engine speed: idle speed (800

± 50 rpm).

– MAF measurement: 310 mg/str

± 5%.

– EGR valve: between 10% and 40%.

• Refer to “DTC P0100: Mass or Volume Air Flow Circuit

Malfunction” for 2.DEF, for the MAF sensor checks.

Is there in good condition?

MAF sensor correct.

Replace the MAF
sensor if necessary.

Step

Action

Yes

No

1

Engine stopped:
Check manually if the variable geometry control rod is
blocked.

Is the rod blocked?

Replace the
turbocharger.

Go to Step 2.

2

At idle speed, with boost pressure control solenoid valve
control:
between of 70% and 85% opening cyclic ratio, disconnect
the electrical connector of the solenoid valve and check at
the same time if the rod controlling the variable geometry
blades moves.

Does the rod move from end stop to end stop?

The turbocharging
control circuit is
operating normally.

Go to Step 3.

3

Check the condition of the boost pressure control solenoid
valve connectors (corrosion, bent pins, etc.). Measure the
resistance of the solenoid valve referring to “Boost Pressure
Control Solenoid Valve Inspection in Section 1C”.

Is the solenoid valve in order?

Go to Step 4.

Replace the boost
pressure control
solenoid valve.

4

Check the electric harness of boost pressure control
solenoid valve

Is there in good condition?

Go to step 5.

Repair as necessary.

1A-108 Engine General Information and Diagnosis:

Test 6: Rotating part of a turbocharger

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5

Reconnect the electrical connector of the boost pressure
control solenoid valve.
On the control diaphragm of the variable geometry blades,
disconnect the pipe coming from the solenoid valve.
Connect a pressure gauge in place of the diaphragm.
Engine at idling speed.

Is the vacuum pressure > 750 mbar?

Replace the
turbocharger.

Go to Step 6.

6

Measure the vacuum pressure upstream of the boost
pressure control solenoid valve.

Is the vacuum pressure > 750 mbar?

Replace the boost
pressure control
solenoid valve.

Check the vacuum
circuit and repeat the
test from the vacuum
pressure check.

Step

Action

Yes

No

Step

Action

Yes

No

1

With the engine cold and stopped, remove the air inlet duct
from the turbocharger, check manually if the compressor
and turbine shaft turns.

Does the shaft turn?

Go to Step 2.

Replace the
turbocharger. Seizing of
the turbocharger could
be caused by poor
lubrication of the
bearings. Check the
lubrication circuit for any
blockage and check the
engine oil pressure.
Perform an oil change
and change the oil filter.

2

Perform a visual inspection of the condition of the
compressor and turbine wheels. ([A]: Deformed, twisted
blade (“soft” foreign body), [B]: Broken blades (“hard” foreign
body))

Are the compressor and turbine wheels in good condition?

Go to Step 3.

• Replace the

turbocharger.

• Replace the duct

connected to the
damaged wheel.

I5JB0B110014-01