Content .. 485 486 487 488 ..

Nissan Frontier D40. Manual - part 487

P0171, P0174 FUEL INJECTION SYSTEM FUNCTION

EC-639

< COMPONENT DIAGNOSIS >

[VQ40DE]

OK or NG

>> GO TO 12.

>> Perform trouble diagnosis for FUEL INJECTOR, refer to

EC-858, "Component Description"

CHECK FUNCTION OF FUEL INJECTOR-I

Without CONSULT-III

Stop engine.

Disconnect harness connector F44 (3), F201 (1)

Turn ignition switch ON.

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

Turn ignition switch OFF.

Disconnect ECM harness connector.

Check harness continuity between harness connector F44 and
ECM as follows.
Refer to Wiring Diagram.

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

OK or NG

>> GO TO 10.

>> Perform trouble diagnosis for FUEL INJECTOR, refer to

EC-858, "Component Description"

10.

CHECK FUNCTION OF FUEL INJECTOR-II

Provide battery voltage between harness connector F201 as follows
and then interrupt it. Listen to each fuel injector operating sound.

OK or NG

: Vacuum tank

: Front

AWBIA0686ZZ

Voltage: Battery voltage

Cylinder

Harness connector F44

terminal

ECM terminal

Continuity should exist.

PBIB2633E

Cylinder

Harness connector F201 terminal

(+)

(–)

Operating sound should exist.

PBIB2634E

EC-640

< COMPONENT DIAGNOSIS >

[VQ40DE]

P0171, P0174 FUEL INJECTION SYSTEM FUNCTION

>> GO TO 12.

>> Perform trouble diagnosis for FUEL INJECTOR, refer to

EC-858, "Component Description"

11.

CHECK FUNCTION OF FUEL INJECTOR

Start engine.

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

OK or NG

>> GO TO 12.

>> Perform trouble diagnosis for FUEL INJECTOR, refer to

EC-858, "Component Description"

12.

CHECK FUEL INJECTOR

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

Turn ignition switch OFF.

Disconnect all injector harness connectors.

Remove fuel tube assembly. Refer to

EM-159, "Removal and Installation"

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

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

Disconnect all ignition coil harness connectors.

Prepare pans or saucers under each fuel injector.

Crank engine for about 3 seconds.
For DTC P0171, check that fuel sprays out from fuel injectors on
bank 1.
For DTC P0174, check that fuel sprays out from fuel injectors on
bank 2.

OK or NG

>> GO TO 13.

>> Replace fuel injectors from which fuel does not spray

out. Always replace O-ring with new ones.

13.

CHECK INTERMITTENT INCIDENT

Refer to

GI-46, "Intermittent Incident"

>> INSPECTION END

Clicking noise should exist.

PBIB1986E

Fuel should be sprayed evenly for each fuel injector.

PBIB1726E

P0172, P0175 FUEL INJECTION SYSTEM FUNCTION

EC-641

< COMPONENT DIAGNOSIS >

[VQ40DE]

P0172, P0175 FUEL INJECTION SYSTEM FUNCTION

On Board Diagnosis Logic

INFOID:0000000005273608

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 illluminates the MIL (2 trip detection logic).

DTC Confirmation Procedure

INFOID:0000000005551333

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-III

Start engine and warm it up to normal operating temperature.

Turn ignition switch OFF and wait at least 10 seconds.

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

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

Start engine.
If it is difficult to start engine, the fuel injection system has a malfunction.
Performing the following procedure is advised.

Crank engine while depressing accelerator pedal.
NOTE:
When depressing accelerator pedal three-fourths (3/4) or more, the control system does not start the
engine. Do not depress accelerator pedal too much.

If engine starts, go to

EC-175, "Diagnosis Procedure"

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

Keep engine at idle for at least 5 minutes.

Check 1st trip DTC.

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

EC-

175, "Diagnosis Procedure"

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

Turn ignition switch OFF and wait at least 10 seconds.

Start engine.

Maintain the following conditions for at least 10 consecutive minutes.
Hold the accelerator pedal as steady as possible.

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)

EC-642

< COMPONENT DIAGNOSIS >

[VQ40DE]

P0172, P0175 FUEL INJECTION SYSTEM FUNCTION

CAUTION:

Always drive vehicle at a safe speed.

Check 1st trip DTC.

If 1st trip DTC is detected, go to

EC-175, "Diagnosis Procedure"

WITH GST

Start engine and warm it up to normal operating temperature.

Turn ignition switch OFF and wait at least 10 seconds.

Disconnect mass air flow sensor harness connector.

Restart engine and let it idle for at least 5 seconds.

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

Select Service $03 with GST. Check that DTC P0102 is
detected.

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

Start engine.
If it is difficult to start engine, the fuel injection system has a mal-
function.
Performing the following procedure is advised.

If engine starts, go to

EC-175, "Diagnosis Procedure"

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

Keep engine at idle for at least 5 minutes.

10. Check 1st trip DTC.

11. The 1st trip DTC P0172 or P0175 should be detected at this stage, if a malfunction exists. If so, go to

EC-

175, "Diagnosis Procedure"

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

Turn ignition switch OFF and wait at least 10 seconds.

Start engine.

Maintain the following conditions for at least 10 consecutive minutes.
Hold the accelerator pedal as steady as possible.

CAUTION:

Always drive vehicle at a safe speed.

Check 1st trip DTC.

If 1st trip DTC is detected, go to

EC-175, "Diagnosis Procedure"

Diagnosis Procedure

INFOID:0000000005273610

CHECK EXHAUST GAS LEAK

Start engine and run it at idle.

VHCL SPEED SE

50 - 120 km/h (31 - 75 MPH)

VHCL SPEED SE

50 - 120 km/h (31 - 75 MPH)

BBIA0541E

Content .. 485 486 487 488 ..