Suzuki Grand Vitara JB416 / JB420 / JB419. Manual — part 106

1A-371 Engine General Information and Diagnosis: For Diesel Engine Model

Test 4: MAF sensor

S6JB0A1124169

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:

For Diesel Engine Model” 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: For Diesel Engine Model
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.

Engine General Information and Diagnosis: For Diesel Engine Model 1A-372

Test 6: Rotating part of a turbocharger

S6JB0A1124171

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

1A-373 Engine General Information and Diagnosis: For Diesel Engine Model

Test 7: Exhaust gas recirculation valve

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3

Manually check the axial play of the wheels. ([A]: Axial play,
[B]: Radial play)

The significant axial play is approximately 2 mm (0.080 in.).
Does the turbo have too much play in the shaft?

Replace the
turbocharger. If the
rotating part is broken:
change the engine oil
and the oil filter.
clean the intercooler
and the air circuit ducts.

The rotating part is in
order.

Step

Action

Yes

No

I5JB0B110015-01

Step

Action

Yes

No

1

VALVE POSITION FAULT FINDING:
Or detection of a leak in the exhaust gas recirculation valve
Clear the faults.
Use “Initialize EGR valve data” on SUZUKI scan tool
command to try to reinitialise the operating values of the
EGR valve.
Switch OFF the ignition and wait 40 seconds.
Switch the ignition back on and check for faults.
If the fault is still present:
• Switch OFF the vehicle ignition.
• Disconnect the connector of the EGR valve.
• Remove the EGR valve referring to “EGR Valve Removal

and Installation: For F9Q Engine in Section 1D” and
reconnect it after having removed it.

• Check that no particles are blocking the movement of the

EGR valve flap.

• Check that the EGR valve is not stuck or jammed in one

position.

• Switch ON the ignition again.
• Check the movement of the valve with displaying “EGR

position sensor” on Data List of SUZUKI scan tool (0 to
2.5 mm travel for an opening cyclic ratio of 40% and when
fully open, ~ 5 mm, for an opening cyclic ratio of 95%).

• Check that the EGR valve flap closes completely.

Is there in good condition?

Go to Step 2.

Replace the EGR valve
referring to “EGR Valve
Removal and
Installation: For F9Q
Engine in Section 1D”.

2

EGR VALVE BUSHING FAULT FINDING:
Remove the EGR valve referring to “EGR Valve Removal
and Installation: For F9Q Engine in Section 1D” the EGR
valve should not contain a cluster of soot between the base
and the valve.
Clean the EGR valve sleeve if necessary.

Is there in good condition?

Go to Step 3.

Replace the EGR valve
referring to “EGR Valve
Removal and
Installation: For F9Q
Engine in Section 1D”.

Engine General Information and Diagnosis: For Diesel Engine Model 1A-374

Test 8: Injector malfunction

S6JB0A1124173

WARNING

!

When servicing fuel system, be sure to observe WARNING in “Precautions on Fuel System Service:
For Diesel Engine Model in Section 1G” to reduce the risk of fire and personal injury.

3

1) Use “Initialize EGR valve data” on SUZUKI scan tool

command to try to reinitialise the operating values of the
EGR valve.

2) Check the air circuit referring to “Test 3: Checking the

turbocharged air inlet circuit: For Diesel Engine Model”.

3) Check the MAF sensor referring to “Test 4: MAF sensor:

For Diesel Engine Model”.

Is there in good condition?

Go to Step 4.

Repair as necessary.

4

Confirmation of the fault finding:
• Start the vehicle.
• Leave the engine at idling speed for 1 min.
• Accelerate very slowly up to 1500 rpm for 2 mins until the

exhaust gas recirculation function becomes active.

• Carry out a vehicle test at low speed, without accelerating

heavily, then normally.

• Check for faults using SUZUKI scan tool.

Does customer complaint or the faults recur?

Substitute a known-
good ECM and recheck.

Exhaust gas
recirculation valve
correct.

Step

Action

Yes

No

Step

Action

Yes

No

1

CHECK THE FUEL REGULATION BALANCE, INJECTOR
BY INJECTOR
• With the engine at idle speed, coolant temperature > 80

°C, 176 °F, display the each injector fuel flow correction
values “Cyl # FF Correction” on Data List of SUZUKI scan
tool.

The normal value for fuel flow correction for an injector is

±

1.0 mm

3

/stroke.

This tolerance may increase with time, but indicates an
injector/cylinder fault if it exceeds

± 5.0 mm

3

/ stroke.

Do one of these values exceed

±

5.0 mm

3

/stroke?

Go to Step 2.

Go to Step 4.