Infiniti M35/M45 Y50. Manual - part 460

DTC P0171, P0174 FUEL INJECTION SYSTEM FUNCTION

EC-313

[VQ35DE]

C

D

E

F

G

H

I

J

K

L

M

A

EC

BANK 2

TBWT0957E

EC-314

[VQ35DE]

DTC P0171, P0174 FUEL INJECTION SYSTEM FUNCTION

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

CAUTION:

Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECMs 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-

MINAL 

NO.

WIRE 

COLOR

ITEM

CONDITION

DATA (DC Voltage)

24

O

A/F sensor 1 heater
(bank 2)

[Engine is running]

●

Warm-up condition

●

Idle speed

Approximately 5V

40
41
42

V/R
P/L
R/W

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

GR/L

A/F sensor 1 (bank 2)

[Engine is running]

●

Warm-up condition

●

Idle speed

Approximately 2.6V

58

LG/B

Approximately 2.3V

76

W/L

Approximately 3.1V

77

Y

Approximately 2.3V

PBIB1584E

PBIB0042E

PBIB0043E

DTC P0171, P0174 FUEL INJECTION SYSTEM FUNCTION

EC-315

[VQ35DE]

C

D

E

F

G

H

I

J

K

L

M

A

EC

Diagnostic Procedure

NBS004XV

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

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.

PBIB1922E

EC-316

[VQ35DE]

DTC P0171, P0174 FUEL INJECTION SYSTEM FUNCTION

3. 

CHECK A/F SENSOR 1 INPUT SIGNAL CIRCUIT

1.

Turn ignition switch OFF.

2.

Disconnect corresponding 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 power.

OK or NG

OK

>> GO TO 4.

NG

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

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.

PBIB2794E