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Infiniti I30. Emission Control System (2003 year). Manual - part 18

CHECK FUNCTION OF INJECTORS

With CONSULT-II

1. Start engine.
2. Perform “POWER BALANCE” in “ACTIVE TEST” mode with CONSULT-II.

SEC136D

3. Make sure that each circuit produces a momentary engine speed drop.

Without CONSULT-II

1. Start engine.
2. Listen to each injector operating sound.

PBIB1725E

Clicking noise should be heard.

OK or NG

䊳

GO TO 7.

䊳

Perform trouble diagnosis for “INJECTORS”, EC-688.

IDX

DTC P0171, P0174 FUEL INJECTION SYSTEM FUNCTION

Diagnostic Procedure (Cont’d)

EC-273

CHECK 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 injector gallery assembly. Refer to EC-57.

Keep fuel hose and all injectors connected to injector gallery.

5. For DTC P0171, reconnect injector harness connectors on bank 1.

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

6. Disconnect all ignition coil harness connectors.
7. Prepare pans or saucers under each injector.
8. Crank engine for about 3 seconds.

For DTC P0171, make sure that fuel sprays out from injectors on bank 1.
For DTC P0174, make sure that fuel sprays out from injectors on bank 2.

PBIB1726E

Fuel should be sprayed evenly for each injector.

OK or NG

䊳

GO TO 8.

䊳

Replace injectors from which fuel does not spray out. Always replace O-ring with new
ones.

CHECK INTERMITTENT INCIDENT

Refer to “TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT”, EC-151.

䊳

INSPECTION END

DTC P0171, P0174 FUEL INJECTION SYSTEM FUNCTION

Diagnostic Procedure (Cont’d)

EC-274

On Board Diagnosis Logic

NHEC0916

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 condi-
tion as the fuel injection system malfunction and light up the MIL
(2 trip detection logic).

Sensor

Input Signal to ECM

ECM func-

tion

Actuator

Heated oxygen sensors 1

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

Fuel injec-
tion control

Injectors

DTC No.

Trouble diagnosis

name

DTC Detecting Condition

Possible Cause

P0172
0172
(Bank 1)
P0175
0175
(Bank 2)

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.)

쐌

Heated oxygen sensor 1

쐌

Injectors

쐌

Exhaust gas leaks

쐌

Incorrect fuel pressure

쐌

Mass air flow sensor

SEF968Y

DTC Confirmation Procedure

NHEC0917

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

NHEC0917S01

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-LEARN CON-
TROL” in “WORK SUPPORT” mode with CONSULT-II.

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

Select “DATA MONITOR” mode with CONSULT-II.

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 “Diagnostic
Procedure”, EC-279.

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

Crank engine while depressing accelerator pedal.
If engine starts, go to “Diagnostic Procedure”, EC-279. If
engine does not start, remove ignition plugs and check for
fouling, etc.

IDX

DTC P0172, P0175 FUEL INJECTION SYSTEM FUNCTION

On Board Diagnosis Logic

EC-275

SEC055D

WITH GST

NHEC0917S02

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. Then
restart and run engine for at least 5 seconds at idle speed.

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

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

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

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

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 “Diagnostic Procedure”, EC-279.

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

10) Crank engine while depressing accelerator pedal.

If engine starts, go to “Diagnostic Procedure”, EC-279. If
engine does not start, remove ignition plugs and check for
fouling, etc.

DTC P0172, P0175 FUEL INJECTION SYSTEM FUNCTION

DTC Confirmation Procedure (Cont’d)

EC-276

Wiring Diagram

NHEC0918

BANK 1

NHEC0918S01

MEC545D

IDX

DTC P0172, P0175 FUEL INJECTION SYSTEM FUNCTION

Wiring Diagram

EC-277

BANK 2

NHEC0918S02

MEC546D

DTC P0172, P0175 FUEL INJECTION SYSTEM FUNCTION

Wiring Diagram (Cont’d)

EC-278

Diagnostic Procedure

NHEC0919

CHECK EXHAUST GAS LEAK

1. Start engine and run it at idle.
2. Listen for an exhaust gas leak before three way catalyst (manifold).

SEC502D

OK or NG

䊳

GO TO 2.

䊳

Repair or replace.

CHECK FOR INTAKE AIR LEAK

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

OK or NG

䊳

GO TO 3.

䊳

Repair or replace.

CHECK HEATED OXYGEN SENSOR 1 CIRCUIT FOR OPEN AND SHORT

1. Turn ignition switch “OFF”.
2. Disconnect corresponding heated oxygen sensor 1 harness connector.
3. Disconnect ECM harness connector.
4. Check harness continuity between ECM terminal and HO2S1 terminal as follows.

Refer to Wiring Diagram.

MTBL1156

Continuity should exist.

5. Check harness continuity between ECM terminal or HO2S1 terminal and ground as follows.

Refer to Wiring Diagram.

MTBL1157

Continuity should not exist.

6. Also check harness for short to power.

OK or NG

䊳

GO TO 4.

䊳

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

IDX

DTC P0172, P0175 FUEL INJECTION SYSTEM FUNCTION

Diagnostic Procedure

EC-279

CHECK FUEL PRESSURE

1. Release fuel pressure to zero. Refer to EC-56.
2. Install fuel pressure gauge and check fuel pressure. Refer to EC-56.

At idling:

Approximately 350 kPa (3.57 kg/cm

, 51 psi)

OK or NG

䊳

GO TO 5.

䊳

Follow the instruction of “Fuel Pressure Check”, EC-56.

CHECK MASS AIR FLOW SENSOR

With CONSULT-II

1. Install all removed parts.
2. Check “MASS AIR FLOW” in “DATA MONITOR” mode with CONSULT-II.

2.0 - 6.0 g·m/sec: at idling
7.0 - 20.0 g·m/sec: at 2,500 rpm

With GST

1. Install all removed parts.
2. Check mass air flow sensor signal in MODE 1 with GST.

2.0 - 6.0 g·m/sec: at idling
7.0 - 20.0 g·m/sec: at 2,500 rpm

OK or NG

䊳

GO TO 6.

䊳

Check connectors for rusted terminals or loose connections in the mass air flow sensor
circuit or engine grounds. Refer to EC-194.

DTC P0172, P0175 FUEL INJECTION SYSTEM FUNCTION

Diagnostic Procedure (Cont’d)

EC-280

CHECK FUNCTION OF INJECTORS

With CONSULT-II

1. Start engine.
2. Perform “POWER BALANCE” in “ACTIVE TEST” mode with CONSULT-II.

SEC136D

3. Make sure that each circuit produces a momentary engine speed drop.

Without CONSULT-II

1. Start engine.
2. Listen to each injector operating sound.

PBIB1725E

Clicking noise should be heard.

OK or NG

䊳

GO TO 7.

䊳

Perform trouble diagnosis for “INJECTORS”, EC-688.

CHECK INJECTOR

1. Remove injector assembly. Refer to EC-57.

Keep fuel hose and all injectors connected to injector gallery.

2. Confirm that the engine is cooled down and there are no fire hazards near the vehicle.
3. Disconnect all injector harness connectors.
4. Disconnect all ignition coil harness connectors.
5. Prepare pans or saucers under each injectors.
6. Crank engine for about 3 seconds.

Make sure fuel does not drip from injector.

OK or NG

OK (Does not drip.)

䊳

GO TO 8.

NG (Drips.)

䊳

Replace the injectors from which fuel is dripping. Always replace O-ring with new one.

CHECK INTERMITTENT INCIDENT

Refer to “TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT”, EC-151.

䊳

INSPECTION END

IDX

DTC P0172, P0175 FUEL INJECTION SYSTEM FUNCTION

Diagnostic Procedure (Cont’d)

EC-281

SEC082D

Component Description

NHEC0773

The fuel tank temperature sensor is used to detect the fuel tem-
perature inside the fuel tank. The sensor modifies a voltage signal
from the ECM. The modified signal returns to the ECM as the fuel
temperature input. The sensor uses a thermistor which is sensitive
to the change in temperature. The electrical resistance of the ther-
mistor decreases as temperature increases.

SEF012P

<Reference data>

Fuel temperature

°C (°F)

Voltage*

Resistance

Ω

20 (68)

3.5

2.3 - 2.7

50 (122)

2.2

0.79 - 0.90

*: These data are reference values and are measured between ECM terminal 75
(Fuel tank temperature sensor) and body ground.

CAUTION:

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

On Board Diagnosis Logic

NHEC0774

DTC No.

Trouble diagnosis

name

DTC Detecting Condition

Possible Cause

P0181
0181

Fuel tank temperature
sensor circuit range/
performance

Rationally incorrect voltage from the sensor is sent
to ECM, compared with the voltage signals from
engine coolant temperature sensor and intake air
temperature sensor.

쐌

Harness or connectors
(The sensor circuit is open or
shorted.)

쐌

Fuel tank temperature sensor

DTC Confirmation Procedure

NHEC0776

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.

DTC P0181 FTT SENSOR

Component Description

EC-282

SEF174Y

WITH CONSULT-II

NHEC0776S01

Turn ignition switch “ON”.

Select “DATA MONITOR” mode with CONSULT-II.

Wait at least 10 seconds.
If the result is NG, go to “Diagnostic Procedure”, EC-283.
If the result is OK, go to following step.

Check “COOLAN TEMP/S” value.
If “COOLAN TEMP/S” is less than 60°C (140°F), the result will
be OK.
If “COOLAN TEMP/S” is above 60°C (140°F), go to the follow-
ing step.

Cool engine down until “COOLAN TEMP/S” is less than 60°C
(140°F).

Wait at least 10 seconds.

If 1st trip DTC is detected, go to “Diagnostic Procedure”,
EC-283.

WITH GST

NHEC0776S02

Follow the procedure “With CONSULT-II” above.

Diagnostic Procedure

NHEC0778

CHECK FUEL TANK TEMPERATURE SENSOR

1. Remove fuel level sensor unit.
2. Check resistance between fuel level sensor unit and fuel pump terminals 4 and 5 by heating with hot water or heat gun

as shown in the figure.

SEF587X

OK or NG

䊳

GO TO 2.

䊳

Replace fuel level sensor unit.

IDX

DTC P0181 FTT SENSOR

DTC Confirmation Procedure (Cont’d)

EC-283

CHECK INTERMITTENT INCIDENT

쐌

Refer to “TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT”, EC-151.

쐌

Refer to Wiring Diagram, EC-287.

䊳

INSPECTION END

DTC P0181 FTT SENSOR

Diagnostic Procedure (Cont’d)

EC-284

SEC082D

Component Description

NHEC0920

SEF012P

<Reference data>

Fuel temperature

°C (°F)

Voltage*

Resistance

Ω

20 (68)

3.5

2.3 - 2.7

50 (122)

2.2

0.79 - 0.90

*: These data are reference values and are measured between ECM terminal 75
(Fuel tank temperature sensor) and body ground.

CAUTION:

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

On Board Diagnosis Logic

NHEC0921

DTC No.

Trouble diagnosis

name

DTC Detecting Condition

Possible Cause

P0182
0182

Fuel tank temperature
sensor circuit low
input

An excessively low voltage from the sensor is sent
to ECM.

쐌

Harness or connectors
(The sensor circuit is open or
shorted.)

쐌

Fuel tank temperature sensor

P0183
0183

Fuel tank temperature
sensor circuit high
input

An excessively high voltage from the sensor is
sent to ECM.

DTC Confirmation Procedure

NHEC0922

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.

IDX

DTC P0182, P0183 FTT SENSOR

Component Description

EC-285

SEF174Y

WITH CONSULT-II

NHEC0922S01

Turn ignition switch “ON”.

Select “DATA MONITOR” mode with CONSULT-II.

Wait at least 10 seconds.
If the result is NG, go to “Diagnostic Procedure”, EC-288.
If the result is OK, go to following step.

Check “COOLAN TEMP/S” value.
If “COOLAN TEMP/S” is less than 60°C (140°F), the result will
be OK.
If “COOLAN TEMP/S” is above 60°C (140°F), go to the follow-
ing step.

Cool engine down until “COOLAN TEMP/S” is less than 60°C
(140°F).

Wait at least 10 seconds.

If 1st trip DTC is detected, go to “Diagnostic Procedure”,
EC-288.

WITH GST

NHEC0922S02

Follow the procedure “With CONSULT-II” above.

DTC P0182, P0183 FTT SENSOR

DTC Confirmation Procedure (Cont’d)

EC-286

Wiring Diagram

NHEC0923

MEC350E

IDX

DTC P0182, P0183 FTT SENSOR

Wiring Diagram

EC-287

Diagnostic Procedure

NHEC0924

CHECK FUEL TANK TEMPERATURE SENSOR POWER SUPPLY CIRCUIT

1. Turn ignition switch “OFF”.
2. Disconnect fuel level sensor unit and fuel pump harness connector.

SEC082D

3. Turn ignition switch “ON”.
4. Check voltage between fuel level sensor unit terminal 4 and ground with CONSULT-II or tester.

SEC116D

OK or NG

䊳

GO TO 3.

䊳

GO TO 2.

DETECT MALFUNCTIONING PART

Check the following.

쐌

Harness connectors B3, M6

쐌

Harness connectors M81, F49

쐌

Harness for open or short between ECM and fuel level sensor unit and fuel pump

䊳

Repair harness or connector.

CHECK FUEL TANK TEMPERATURE SENSOR GROUND CIRCUIT FOR OPEN AND SHORT

1. Turn ignition switch “OFF”.
2. Check harness continuity between fuel level sensor unit and fuel pump terminal 5 and body ground. Refer to Wiring

Diagram.

Continuity should exist.

3. Also check harness for short to power.

OK or NG

䊳

GO TO 4.

䊳

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

DTC P0182, P0183 FTT SENSOR

Diagnostic Procedure

EC-288

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