Nissan Pathfinder (2006 year). Manual - part 182

DTC P0171, P0174 FUEL INJECTION SYSTEM FUNCTION

EC-315

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2006 Pathfinder

9. 

CHECK FUNCTION OF FUEL INJECTOR-I

 Without CONSULT-II

1.

Stop engine.

2.

Disconnect harness connector F44, F101

3.

Turn ignition switch ON.

4.

Check voltage between harness connector F44 terminal 3 and
ground with CONSULT-II or tester.

5.

Turn ignition switch OFF.

6.

Disconnect ECM harness connector.

7.

Check harness continuity between harness connector F44 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 10.

NG

>> Perform trouble diagnosis for FUEL INJECTOR, refer to 

EC-633

 .

10. 

CHECK FUNCTION OF FUEL INJECTOR-II

Provide battery voltage between harness connector F101 as follows
and then interrupt it. Listen to each fuel injector operating sound.

OK or NG

OK

>> GO TO 12.

NG

>> Perform trouble diagnosis for FUEL INJECTOR, refer to 

EC-633

 .

BBIA0587E

Voltage: Battery voltage

Cylinder

Harness connector F44 

terminal

ECM terminal

1

2

23

3

1

22

5

4

21

Continuity should exist.

PBIB2633E

Cylinder

Harness connector F101 terminal

(+)

(–)

1

3

2

3

3

1

5

3

4

Operating sound should exist.

PBIB2634E

EC-316

DTC P0171, P0174 FUEL INJECTION SYSTEM FUNCTION

2006 Pathfinder

11. 

CHECK FUNCTION OF FUEL INJECTOR

1.

Start engine.

2.

Listen to fuel injectors No.2, No.4, No.6 operating sound.

OK or NG

OK

>> GO TO 12.

NG

>> Perform trouble diagnosis for FUEL INJECTOR, refer to

EC-633

 .

12. 

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.

Disconnect all injector harness connectors.

4.

Remove fuel tube assembly. Refer to 

EM-35, "FUEL INJECTOR AND FUEL TUBE"

 .

Keep fuel hose and all fuel injectors connected to fuel tube.

5.

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

6.

Disconnect all ignition coil harness connectors.

7.

Prepare pans or saucers under each fuel injector.

8.

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 13.

NG

>> Replace fuel injectors from which fuel does not spray

out. Always replace O-ring with new ones.

13. 

CHECK INTERMITTENT INCIDENT

Refer to 

EC-144, "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT"

 .

>> INSPECTION END

Clicking noise should exist.

PBIB1986E

Fuel should be sprayed evenly for each fuel injector.

PBIB1726E

DTC P0172, P0175 FUEL INJECTION SYSTEM FUNCTION

EC-317

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2006 Pathfinder

DTC P0172, P0175 FUEL INJECTION SYSTEM FUNCTION

PFP:16600

On Board Diagnosis Logic

UBS00K7E

With the Air-Fuel Mixture Ratio Self-Learning Control, the actual mixture ratio can be brought closely to the
theoretical mixture ratio based on the mixture ratio feedback signal from the air fuel ratio (A/F) sensor 1. The
ECM calculates the necessary compensation to correct the offset between the actual and the theoretical
ratios.
In case the amount of the compensation value is extremely large (the actual mixture ratio is too rich.), the
ECM judges the condition as the fuel injection system malfunction and lights up the MIL (2 trip detection logic).

DTC Confirmation Procedure

UBS00K7F

NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.

 WITH CONSULT-II

1.

Start engine and warm it up to normal operating temperature.

2.

Turn ignition switch OFF and wait at least 10 seconds.

3.

Turn ignition switch ON and select “SELF-LEARNING CONT” in “WORK SUPPORT” mode with CON-
SULT-II.

4.

Clear the self-learning control coefficient by touching “CLEAR”.

5.

Select “DATA MONITOR” mode with CONSULT-II.

6.

Start engine again and let it idle for at least 10 minutes.
The 1st trip DTC P0172, P0175 should be detected at this stage,
if a malfunction exists. If so, go to 

EC-323, "Diagnostic Proce-

dure"

 .

NOTE:
If 1st trip DTC is not detected during above procedure, perform-
ing the following procedure is advised.

a.

Turn ignition switch OFF and wait at least 10 seconds.

b.

Start engine and drive the vehicle under the similar conditions to
(1st trip) Freeze Frame Data for a certain time. Refer to the table below.
Hold the accelerator pedal as steady as possible.

The similar conditions to (1st trip) Freeze Frame Data means the vehicle operation that the following con-
ditions should be satisfied at the same time.

7.

If it is difficult to start engine at step 6, the fuel injection system has a malfunction, too.

Sensor

Input signal to ECM

ECM function

Actuator

A/F sensor 1

Density of oxygen in exhaust gas
(Mixture ratio feedback signal)

Fuel injection 
control

Fuel injector

DTC No.

Trouble diagnosis 

name

DTC detecting condition

Possible cause

P0172
0172
(Bank 1)

Fuel injection system 
too rich

●

Fuel injection system does not operate properly.

●

The amount of mixture ratio compensation is too 
large. (The mixture ratio is too rich.)

●

Air fuel ratio (A/F) sensor 1

●

Fuel injector

●

Exhaust gas leaks

●

Incorrect fuel pressure

●

Mass air flow sensor

P0175
0175
(Bank 2)

SEF968Y

Engine speed

Engine speed in the freeze frame data 

±

 400 rpm

Vehicle speed

Vehicle speed in the freeze frame data 

±

 10 km/h (6 MPH)

Engine coolant temperature 
(T) condition

When the freeze frame data shows lower than 70 

°

C (158 

°

F),

T should be lower than 70 

°

C (158 

°

F).

When the freeze frame data shows higher than or equal to 70 

°

C (158 

°

F),

T should be higher than or equal to 70 

°

C (158 

°

F).

EC-318

DTC P0172, P0175 FUEL INJECTION SYSTEM FUNCTION

2006 Pathfinder

8.

Crank engine while depressing accelerator pedal.
If engine starts, go to 

EC-323, "Diagnostic Procedure"

 . If engine does not start, remove ignition plugs and

check for fouling, etc.

 WITH GST

1.

Start engine and warm it up to normal operating temperature.

2.

Turn ignition switch OFF and wait at least 10 seconds.

3.

Disconnect mass air flow sensor harness connector. Then
restart and run engine for at least 5 seconds at idle speed.

4.

Stop engine and reconnect mass air flow sensor harness con-
nector.

5.

Select Service $03 with GST. Make sure DTC P0102 is
detected. 

6.

Select Service $04 with GST and erase the DTC P0102.

7.

Start engine again and let it idle for at least 10 minutes.

8.

Select Service $07 with GST. The 1st trip DTC P0172 or P0175
should be detected at this stage, if a malfunction exists. If so, go
to 

EC-323, "Diagnostic Procedure"

 .

NOTE:
If 1st trip DTC is not detected during above procedure, performing the following procedure is advised.

a.

Turn ignition switch OFF and wait at least 10 seconds.

b.

Start engine and drive the vehicle under the similar conditions to (1st trip) Freeze Frame Data for a certain
time. Refer to the table below.
Hold the accelerator pedal as steady as possible.

The similar conditions to (1st trip) Freeze Frame Data means the vehicle operation that the following con-
ditions should be satisfied at the same time.

9.

If it is difficult to start engine at step 7, the fuel injection system has a malfunction.

10. Crank engine while depressing accelerator pedal.

If engine starts, go to 

EC-323, "Diagnostic Procedure"

 . If engine does not start, remove ignition plugs and

check for fouling, etc.

BBIA0541E

Engine speed

Engine speed in the freeze frame data 

±

 400 rpm

Vehicle speed

Vehicle speed in the freeze frame data 

±

 10 km/h (6 MPH)

Engine coolant temperature 
(T) condition

When the freeze frame data shows lower than 70 

°

C (158 

°

F),

T should be lower than 70 

°

C (158 

°

F).

When the freeze frame data shows higher than or equal to 70 

°

C (158 

°

F),

T should be higher than or equal to 70 

°

C (158 

°

F).

DTC P0172, P0175 FUEL INJECTION SYSTEM FUNCTION

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2006 Pathfinder

Wiring Diagram

UBS00K7G

BANK 1

BBWA2368E

EC-320

DTC P0172, P0175 FUEL INJECTION SYSTEM FUNCTION

2006 Pathfinder

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)

2

G

A/F sensor 1 heater
(Bank 1)

[Engine is running]

●

Warm-up condition

●

Idle speed

Approximately 5V

16

BR

A/F sensor 1 (Bank 1)

[Engine is running]

●

Warm-up condition

●

Idle speed

Approximately 3.1V

35

O

Approximately 2.6V

56

LG

Approximately 2.3V

75

P

Approximately 2.3V

21
22
23

W
LG
SB

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

DTC P0172, P0175 FUEL INJECTION SYSTEM FUNCTION

EC-321

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2006 Pathfinder

BANK 2

BBWA2369E

EC-322

DTC P0172, P0175 FUEL INJECTION SYSTEM FUNCTION

2006 Pathfinder

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

G

A/F sensor 1 heater
 (Bank 2)

[Engine is running]

●

Warm-up condition

●

Idle speed

Approximately 5V

40
41
42

V
R
O

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

A/F sensor 1 (Bank 2)

[Engine is running]

●

Warm-up condition

●

Idle speed

Approximately 2.6V

58

O

Approximately 2.3V

76

V

Approximately 3.1V

77

Y

Approximately 2.3V

PBIB1584E

SEC984C

SEC985C