Infiniti F50. Manual - part 408

 

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Infiniti F50. Manual - part 408

 

 

DTC P0171, P0174 FUEL INJECTION SYSTEM FUNCTION

EC-273

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10. 

CHECK INTERMITTENT INCIDENT

Refer to 

EC-132, "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT"

 .

>> INSPECTION END

EC-274

DTC P0172, P0175 FUEL INJECTION SYSTEM FUNCTION

DTC P0172, P0175 FUEL INJECTION SYSTEM FUNCTION

PFP:16600

On Board Diagnosis Logic

EBS00MCQ

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 heated oxygen sensors 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

EBS00MCR

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-278, "Diagnostic Proce-

dure"

 .

7.

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

8.

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

EC-278, "Diagnostic Procedure"

 . If engine

does not start, remove ignition plugs and check for fouling, etc.

Sensor

Input Signal to ECM

ECM function

Actuator

Heated oxygen sensors 1

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

Fuel injection control

Fuel injectors

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.)

Heated oxygen sensor 1

Injectors

Exhaust gas leaks

Incorrect fuel pressure

Mass air flow sensor

P0175
0175
(Bank 2)

SEF968Y

DTC P0172, P0175 FUEL INJECTION SYSTEM FUNCTION

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 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 “MODE 3” with GST. Make sure DTC P0102 is detected.

6.

Select “MODE 4” with GST and erase the DTC P0102.

7.

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

8.

Select “MODE 7” with GST. The 1st trip DTC P0172 or P0175
should be detected at this stage, if a malfunction exists. If so, go
to 

EC-278, "Diagnostic Procedure"

 .

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-278, "Diagnostic Procedure"

 . If engine does not start, check exhaust and intake

air leak visually.

PBIB0012E

EC-276

DTC P0172, P0175 FUEL INJECTION SYSTEM FUNCTION

Wiring Diagram

EBS00MCS

BANK 1

TBWM0151E

 

 

 

 

 

 

 

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