Infiniti G35 (V35). Manual - part 362

DTC P0171, P0174 FUEL INJECTION SYSTEM FUNCTION

EC-329

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4. 

CHECK FUEL PRESSURE

1.

Release fuel pressure to zero. Refer to 

EC-81, "FUEL PRESSURE RELEASE"

 .

2.

Install fuel pressure gauge and check fuel pressure. Refer to 

EC-82, "FUEL PRESSURE CHECK"

 .

OK or NG

OK

>> GO TO 6.

NG

>> GO TO 5.

5. 

DETECT MALFUNCTIONING PART

Check the following.

●

Fuel pump and circuit (Refer to 

EC-659, "FUEL PUMP"

 .)

●

Fuel pressure regulator (Refer to 

EC-82, "FUEL PRESSURE CHECK"

 )

●

Fuel lines (Refer to 

FL-4, "Checking Fuel Lines"

 .)

●

Fuel filter for clogging

>> Repair or replace.

6. 

CHECK MASS AIR FLOW SENSOR

 With CONSULT-II

1.

Install all removed parts.

2.

Check “MASS AIR FLOW” in “DATA MONITOR” mode with CONSULT-II.

 With GST

1.

Install all removed parts.

2.

Check mass air flow sensor signal in Service $01 with GST.

OK or NG

OK (With CONSULT-II)>>GO TO 7.
OK (Without COUSULT-II)>>GO TO 8.
NG

>> Check connectors for rusted terminals or loose connections in the mass air flow sensor circuit or

ground. Refer to 

EC-207, "DTC P0101 MAF SENSOR"

 .

At idling: Approximately 350 kPa (3.57 kg/cm

2

 , 51 psi)

2.0 - 6.0 g·m/sec:

at idling

7.0 - 20.0 g·m/sec:

at 2,500 rpm

2.0 - 6.0 g·m/sec:

at idling

7.0 - 20.0 g·m/sec:

at 2,500 rpm

EC-330

DTC P0171, P0174 FUEL INJECTION SYSTEM FUNCTION

7. 

CHECK FUNCTION OF FUEL INJECTOR

 With CONSULT-II

1.

Start engine.

2.

Perform “POWER BALANCE” in “ACTIVE TEST” mode with
CONSULT-II.

3.

Make sure that each circuit produces a momentary engine
speed drop.

OK or NG

OK

>> GO TO 10.

NG

>> Perform trouble diagnosis for FUEL INJECTOR, refer to 

EC-652, "FUEL INJECTOR"

 .

PBIB0133E

DTC P0171, P0174 FUEL INJECTION SYSTEM FUNCTION

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8. 

CHECK FUNCTION OF FUEL INJECTOR-I

 Without CONSULT-II

1.

Stop engine.

2.

Disconnect harness connectors F33, F221

3.

Turn ignition switch ON.

4.

Check voltage between harness connector F33 terminal 5 and
ground with CONSULT-II or tester.

5.

Turn ignition switch OFF.

6.

Disconnect ECM harness connector.

7.

Check harness continuity between harness connector F33 and
ECM as follows.
Refer to Wiring Diagram.

8.

Also check harness for short to ground and short to power.

OK or NG

OK

>> GO TO 9.

NG

>> Perform trouble diagnosis for FUEL INJECTOR, refer to 

EC-652, "FUEL INJECTOR"

 .

PBIB2479E

Voltage: Battery voltage

Cylinder

Harness connector F33 

terminal

ECM terminal

1

6

23

2

4

42

3

2

22

4

3

41

5

1

21

6

7

40

Continuity should exist.

PBIB2323E

EC-332

DTC P0171, P0174 FUEL INJECTION SYSTEM FUNCTION

9. 

CHECK FUNCTION OF FUEL INJECTOR-II

Provide battery voltage between harness connector F221 as follows
and then interrupt it. Listen to each fuel injector operating sound.

OK or NG

OK

>> GO TO 10.

NG

>> Perform trouble diagnosis for INJECTOR CIRCUIT, refer to 

EC-652, "FUEL INJECTOR"

 .

10. 

CHECK FUEL INJECTOR

1.

Confirm that the engine is cooled down and there are no fire hazards near the vehicle.

2.

Turn ignition switch OFF.

3.

Reconnect all harness connectors disconnected.

4.

Disconnect all fuel injector harness connectors.

5.

Remove fuel injector gallery assembly. Refer to 

EM-38, "FUEL INJECTOR AND FUEL TUBE"

 .

Keep fuel hose and all fuel injectors connected to injector gallery.

6.

For DTC P0171, reconnect fuel injector harness connectors on bank 1.
For DTC P0174, reconnect fuel injector harness connectors on bank 2.

7.

Disconnect all ignition coil harness connectors.

8.

Prepare pans or saucers under each injector.

9.

Crank engine for about 3 seconds.
For DTC P0171, make sure that fuel sprays out from fuel injec-
tors on bank 1.
For DTC P0174, make sure that fuel sprays out from fuel injec-
tors on bank 2.

OK or NG

OK

>> GO TO 11.

NG

>> Replace fuel injectors from which fuel does not spray

out. Always replace O-ring with new ones.

11. 

CHECK INTERMITTENT INCIDENT

Refer to 

EC-151, "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT"

 .

>> INSPECTION END

Cylinder

Harness connector F221 terminal

(+)

(–)

1

5

6

2

4

3

2

4

3

5

1

6

7

Operating sound should exist.

PBIB2497E

Fuel should be sprayed evenly for each injector.

PBIB1726E