Infiniti FX35 / FX45. Manual - part 379

DTC P0171, P0174 FUEL INJECTION SYSTEM FUNCTION

EC-277

< SERVICE INFORMATION >

[VQ35DE]

C

D

E

F

G

H

I

J

K

L

M

A

EC

N

P

O

Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.

: Average voltage for pulse signal (Actual pulse signal can be confirmed by oscilloscope.)

TER-

MI-

NAL 

NO.

WIRE 

COLOR

ITEM

CONDITION

DATA (DC Voltage)

2

R/L

A/F sensor 1 heater
(bank 1)

[Engine is running]
• Warm-up condition
• Idle speed

Approximately 5V

16

G

A/F sensor 1 (bank 1)

[Engine is running]
• Warm-up condition
• Idle speed

Approximately 3.1V

35

B/R

Approximately 2.6V

56

L

Approximately 2.3V

75

R/B

Approximately 2.3V

21
22
23

W
G
R

Fuel injector No. 5
Fuel injector No. 3
Fuel injector No. 1

[Engine is running]
• Warm-up condition
• Idle speed

NOTE:
The pulse cycle changes depending on rpm 
at idle

BATTERY VOLTAGE

(11 - 14V)

[Engine is running]
• Warm-up condition
• Engine speed: 2,000 rpm

BATTERY VOLTAGE

(11 - 14V)

PBIB1584E

SEC984C

SEC985C

EC-278

< SERVICE INFORMATION >

[VQ35DE]

DTC P0171, P0174 FUEL INJECTION SYSTEM FUNCTION

BANK 2

Specification data are reference values and are measured between each terminal and ground.
Pulse signal is measured by CONSULT-III.

CAUTION:

Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.

TBWM1595E

DTC P0171, P0174 FUEL INJECTION SYSTEM FUNCTION

EC-279

< SERVICE INFORMATION >

[VQ35DE]

C

D

E

F

G

H

I

J

K

L

M

A

EC

N

P

O

: Average voltage for pulse signal (Actual pulse signal can be confirmed by oscilloscope.)

Diagnosis Procedure

INFOID:0000000001326104

1.

CHECK EXHAUST GAS LEAK

1.

Start engine and run it at idle.

2.

Listen for an exhaust gas leak before three way catalyst 1.

OK or NG

OK

>> GO TO 2.

NG

>> Repair or replace.

2.

CHECK FOR INTAKE AIR LEAK

TER-

MI-

NAL 

NO.

WIRE 

COLOR

ITEM

CONDITION

DATA (DC Voltage)

24

L

A/F sensor 1 heater
 (bank 2)

[Engine is running]
• Warm-up condition
• Idle speed

Approximately 5V

40
41
42

LG
B
P

Fuel injector No. 6
Fuel injector No. 4 
Fuel injector No. 2

[Engine is running]
• Warm-up condition
• Idle speed

NOTE:
The pulse cycle changes depending on rpm 
at idle

BATTERY VOLTAGE

(11 - 14V)

[Engine is running]
• Warm-up condition
• Engine speed: 2,000 rpm

BATTERY VOLTAGE

(11 - 14V)

57

G

A/F sensor 1 (bank 2)

[Engine is running]
• Warm-up condition
• Idle speed

Approximately 2.6V

58

Y

Approximately 2.3V

76

P

Approximately 3.1V

77

BR

Approximately 2.3V

PBIB1584E

SEC984C

SEC985C

PBIB1922E

EC-280

< SERVICE INFORMATION >

[VQ35DE]

DTC P0171, P0174 FUEL INJECTION SYSTEM FUNCTION

1.

Listen for an intake air leak after the mass air flow sensor.

2.

Check PCV hose connection.

OK or NG

OK

>> GO TO 3.

NG

>> Repair or replace.

3.

CHECK AIR FUEL RATIO (A/F) SENSOR 1 INPUT SIGNAL CIRCUIT

1.

Turn ignition switch OFF.

2.

Disconnect corresponding air fuel ration (A/F) sensor 1 harness connector.

3.

Disconnect ECM harness connector.

4.

Check harness continuity between the following terminals.
Refer to Wiring Diagram.

5.

Check harness continuity between the following terminals and ground.
Refer to Wiring Diagram.

6.

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

OK or NG

OK

>> GO TO 4.

NG

>> Repair open circuit or short to ground or short to power in harness or connectors.

4.

CHECK FUEL PRESSURE

1.

Release fuel pressure to zero. Refer to 

EC-87, "Fuel Pressure Check"

.

2.

Install fuel pressure gauge and check fuel pressure. Refer to 

EC-87, "Fuel Pressure Check"

.

A/F sensor 1 terminal

ECM terminal

Bank 1

1

16

2

75

5

35

6

56

Bank 2

1

76

2

77

5

57

6

58

Continuity should exist.

Bank 1

Bank 2

A/F sensor 1 terminal

ECM terminal

A/F sensor 1 terminal

ECM terminal

1

16

1

76

2

75

2

77

5

35

5

57

6

56

6

58

Continuity should not exist.

PBIB2190E