Infiniti I30. Emission Control System (2003 year). Manual — part 27

12) Check “FUEL LEVEL SE” output voltage and confirm whether

the voltage changes more than 0.03V during step 7 to 11.
If NG, check the fuel level sensor, refer to EL-140, “FUEL
LEVEL SENSOR UNIT CHECK”.

SEC910C

WITH GST

NHEC0998S02

NOTE:
Start from step 11, if it is possible to confirm that the fuel
cannot be drained by 30

(7-7/8 US gal, 6-5/8 Imp gal) in

advance.
1)

Prepare a fuel container and a spare hose.

2)

Release fuel pressure from fuel line, refer to “Fuel Pressure
Release”, EC-56.

3)

Remove the fuel feed hose on the fuel level sensor unit.

4)

Connect a spare fuel hose where the fuel feed hose was
removed.

5)

Turn ignition switch “OFF”.

6)

Set voltmeters probe between ECM terminal 69 (fuel level
sensor signal) and ground.

7)

Turn ignition switch “ON”.

8)

Check voltage between ECM terminal 69 and ground and note
it.

9)

Drain fuel by 30

(7-7/8 US gal, 6-5/8 Imp gal) from the fuel

tank using proper equipment.

10) Fill fuel into the fuel tank for 30

(7-7/8 US gal, 6-5/8 Imp gal).

11) Confirm that the voltage between ECM terminal 69 and ground

changes more than 0.03V during step 8 - 10.
If NG, check component of fuel level sensor, refer to EL-140,
“FUEL LEVEL SENSOR UNIT CHECK”.

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DTC P0461 FUEL LEVEL SENSOR

Overall Function Check (Cont’d)

EC-417

SEC088D

Component Description

NHEC0999

The fuel level sensor is mounted in the fuel level sensor unit. The
sensor detects a fuel level in the fuel tank and transmits a signal
to the ECM.
It consists of two parts, one is mechanical float and the other side
is variable resistor. Fuel level sensor output voltage changes
depending on the movement of the fuel mechanical float.

On Board Diagnostic Logic

NHEC1000

ECM receives two signals from the fuel level sensor circuit.
One is fuel level sensor power supply circuit, and the other is fuel
level sensor ground circuit.
This diagnosis indicates the former, to detect open or short circuit
malfunction.

DTC No.

Trouble diagnosis

name

DTC Detecting Condition

Possible Cause

P0462
0462

Fuel level sensor cir-
cuit low input

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

쐌

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

쐌

Fuel level sensor

P0463
0463

Fuel level sensor cir-
cuit high input

An excessively high voltage is sent from the sen-
sor is sent to ECM.

DTC Confirmation Procedure

NHEC1001

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.
TESTING CONDITION:
Before performing the following procedure, confirm that bat-
tery voltage is more than 11V at ignition switch “ON”.

SEF195Y

WITH CONSULT-II

NHEC1001S01

1)

Turn ignition switch “ON”.

2)

Select “DATA MONITOR” mode with CONSULT-II.

3)

Wait at least 5 seconds.

4)

If 1st trip DTC is detected, go to “Diagnostic Procedure”,
EC-420.

WITH GST

NHEC1001S02

Follow the procedure “WITH CONSULT-II” above.

DTC P0462, P0463 FUEL LEVEL SENSOR

Component Description

EC-418

Wiring Diagram

NHEC1002

MEC357E

SEF711YB

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DTC P0462, P0463 FUEL LEVEL SENSOR

Wiring Diagram

EC-419

Diagnostic Procedure

=NHEC1003

1

CHECK FUEL LEVEL SENSOR POWER SUPPLY CIRCUIT

1. Turn ignition switch “OFF”.
2. Disconnect fuel level sensor unit and fuel pump harness connector.
3. Turn ignition switch “ON”.
4. Check voltage between fuel level sensor unit and fuel pump terminal 2 and ground with CONSULT-II or tester.

SEC220D

Voltage: Battery voltage

OK or NG

OK

䊳

GO TO 3.

NG

䊳

GO TO 2.

2

DETECT MALFUNCTIONING PART

Check the following.

쐌

Harness connectors M6, B3

쐌

Harness for open or short between combination meter and fuel level sensor unit

䊳

Repair or replace harness or connectors.

3

CHECK FUEL LEVEL SENSOR GROUND CIRCUIT FOR OPEN AND SHORT

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

Continuity should exist.

3. Also check harness for short to power.

OK or NG

OK

䊳

GO TO 4.

NG

䊳

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

4

CHECK FUEL LEVEL SENSOR INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT

1. Disconnect ECM harness connector.
2. Check harness continuity between ECM terminal 69 and fuel level sensor and fuel pump terminal 2. Refer to Wiring

Diagram.

Continuity should exist.

3. Also check harness for short to power.

OK or NG

OK

䊳

GO TO 6.

NG

䊳

GO TO 5.

DTC P0462, P0463 FUEL LEVEL SENSOR

Diagnostic Procedure

EC-420

5

DETECT MALFUNCTIONING PART

Check the following.

쐌

Harness connectors F66, M229

쐌

Harness connectors M6, B3

쐌

Harness for open between ECM and fuel level sensor

䊳

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

6

CHECK FUEL LEVEL SENSOR

Refer to EL-140, “Fuel Level Sensor Unit Check”.

OK or NG

OK

䊳

GO TO 7.

NG

䊳

Replace fuel level sensor unit.

7

CHECK INTERMITTENT INCIDENT

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

䊳

INSPECTION END

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DTC P0462, P0463 FUEL LEVEL SENSOR

Diagnostic Procedure (Cont’d)

EC-421

Component Description

=NHEC1004

The vehicle speed sensor signal is sent from ABS actuator and
electric unit or ABS/TCS control unit to combination meter. The
combination meter then sends a signal to the ECM.

On Board Diagnosis Logic

NHEC1006

DTC No.

Trouble diagnosis

name

DTC Detecting Condition

Possible Cause

P0500
0500

Vehicle speed sensor

The almost 0 km/h (0 MPH) signal from vehicle
speed sensor signal is sent to ECM even when
vehicle is being driven.

쐌

Harness or connector
(The vehicle speed sensor signal cir-
cuit is open or shorted.)

쐌

ABS actuator and electric unit or
ABS/TCS control unit

쐌

Combination meter

DTC Confirmation Procedure

NHEC1007

CAUTION:

Always drive vehicle at a safe speed.
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.
TESTING CONDITION:
Steps 1 and 2 may be conducted with the drive wheels lifted
in the shop or by driving the vehicle. If a road test is expected
to be easier, it is unnecessary to lift the vehicle.

SEF196Y

WITH CONSULT-II

NHEC1007S01

1)

Start engine.

2)

Read “VHCL SPEED SE” in “DATA MONITOR” mode with
CONSULT-II. The vehicle speed on CONSULT-II should
exceed 10 km/h (6 MPH) when rotating wheels with suitable
gear position.
If NG, go to “Diagnostic Procedure”, EC-425.
If OK, go to following step.

3)

Select “DATA MONITOR” mode with CONSULT-II.

4)

Warm engine up to normal operating temperature.

5)

Maintain the following conditions for at least 10 consecutive
seconds.

ENG SPEED

More than 1,800 rpm

COOLAN TEMP/S

More than 70°C (158°F)

B/FUEL SCHDL

5.5 - 14.0 msec

Selector lever

Suitable position

PW/ST SIGNAL

OFF

6)

If 1st trip DTC is detected, go to “Diagnostic Procedure”,
EC-425.

DTC P0500 VSS

Component Description

EC-422

Overall Function Check

NHEC1008

Use this procedure to check the overall function of the vehicle
speed sensor signal circuit. During this check, a 1st trip DTC might
not be confirmed.

WITH GST

NHEC1008S01

1)

Lift up drive wheels.

2)

Start engine.

3)

Read vehicle speed sensor signal in “MODE 1” with GST.
The vehicle speed sensor signal on GST should be able to
exceed 10 km/h (6 MPH) when rotating wheels with suitable
gear position.

4)

If NG, go to “Diagnostic Procedure”, EC-425.

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DTC P0500 VSS

Overall Function Check

EC-423

Wiring Diagram

=NHEC1009

MEC358E

SEC045D

DTC P0500 VSS

Wiring Diagram

EC-424

Diagnostic Procedure

NHEC1010

1

CHECK VEHICLE SPEED SENSOR INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT

1. Turn ignition switch “OFF”.
2. Disconnect ECM harness connector and combination meter harness connector M32.
3. Check harness continuity between ECM terminal 68 and combination meter terminal 32.

Refer to Wiring Diagram.

Continuity should exist.

4. Also check harness for short to power.

OK or NG

OK

䊳

GO TO 3.

NG

䊳

GO TO 2.

2

DETECT MALFUNCTIONING PART

Check the following.

쐌

Harness connectors M229, F66

쐌

Harness for open or short between ECM and combination meter

䊳

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

3

CHECK COMBINATION METER FUNCTION

Make sure that speedometer functions properly.

OK or NG

OK

䊳

GO TO 5.

NG

䊳

GO TO 4.

4

CHECK COMBINATION METER CIRCUIT FOR OPEN AND SHORT

Check the following.

쐌

Harness connectors M15, E81

쐌

Harness connectors M230, F67

쐌

Harness connectors F65, F114

쐌

Harness for open or short between combination meter and vehicle speed sensor

쐌

Harness for open or short between combination meter and ABS/TCS control unit

쐌

Harness for open or short between vehicle speed sensor and ECM

쐌

Harness for open or short between vehicle speed sensor and TCM (Transmission control module)

OK or NG

OK

䊳

Check combination meter and vehicle speed sensor or ABS/TCS control unit. Refer to EL
section.

NG

䊳

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

5

CHECK INTERMITTENT INCIDENT

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

䊳

INSPECTION END

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DTC P0500 VSS

Diagnostic Procedure

EC-425

Description

NHEC0787

NOTE:
If DTC P0506 is displayed with other DTC, first perform the trouble diagnosis for the other DTC.
The ECM controls the engine idle speed to a specified level through the fine adjustment of the air, which is
let into the intake manifold, by operating the electric throttle control actuator. The operating of the throttle valve
is varied to allow for optimum control of the engine idling speed. The crankshaft position sensor (POS) detects
the actual engine speed and sends a signal to the ECM.
The ECM controls the electric throttle control actuator so that the engine speed coincides with the target value
memorized in the ECM. The target engine speed is the lowest speed at which the engine can operate steadly.
The optimum value stored in the ECM is determined by taking into consideration various engine conditions,
such as during warming up, deceleration, and engine load (air conditioner, power steering and cooling fan
operation, etc.).

On Board Diagnosis Logic

NHEC0790

DTC No.

Trouble diagnosis

name

DTC Detecting Condition

Possible Cause

P0506
0506

Idle speed control
system RPM lower
than expected

The idle speed is not in the specified range.

쐌

Electric throttle control actuator

쐌

Intake air leak

DTC Confirmation Procedure

NHEC0792

NOTE:

쐌

If

“DTC

Confirmation

Procedure”

has

been

previously

conducted, always turn ignition switch “OFF” and wait at least
10 seconds before conducting the next test.

쐌

If the target idle speed is out of the specified value, per-
form “Idle Air Volume Learning” before conducting “DTC
Confirmation Procedure”. For the target idle speed, refer
to the “Service Data and Specifications (SDS)”, EC-730.

TESTING CONDITION:

쐌

Before performing the following procedure, confirm that
battery voltage is more than 11V at idle.

쐌

Always perform the test at a temperature above −10°C
(14°F).

SEF174Y

WITH CONSULT-II

NHEC0792S03

1)

Open engine hood.

2)

Start engine and warm it up to normal operating temperature.

3)

Turn ignition switch “OFF” and wait at least 10 seconds.

4)

Turn ignition switch “ON” again and select “DATA MONITOR”
mode with CONSULT-II.

5)

Start engine and run it for at least 1 minute at idle speed.

6)

If 1st trip DTC is detected, go to “Diagnostic Procedure”,
EC-427.

DTC P0506 ISC SYSTEM

Description

EC-426

WITH GST

NHEC0792S04

Follow the procedure “With CONSULT-II” above.

Diagnostic Procedure

NHEC0794

1

CHECK INTAKE AIR LEAK

1. Start engine and let it idle.
2. Listen for an intake air leak after the mass air flow sensor.

OK or NG

OK

䊳

GO TO 2.

NG

䊳

Discover air leak location and repair.

2

REPLACE ECM

1. Stop engine.
2. Replace ECM.
3. Perform initialization of IVIS (NATS) system and registration of all IVIS (NATS) ignition key IDs. Refer to “IVIS (INFINITI

VEHICLE IMMOBILIZER SYSTEM — NATS)”, EC-90.

4. Perform “Accelerator Pedal Released Position Learning”, EC-71.
5. Perform “Throttle Valve Closed Position Learning”, EC-71.
6. Perform “Idle Air Volume Learning”, EC-71.

䊳

INSPECTION END

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DTC P0506 ISC SYSTEM

DTC Confirmation Procedure (Cont’d)

EC-427

Description

NHEC0795

NOTE:
If DTC P0507 is displayed with other DTC, first perform the trouble diagnosis for the other DTC.
The ECM controls the engine idle speed to a specified level through the fine adjustment of the air, which is
let into the intake manifold, by operating the electric throttle control actuator. The operating of the throttle valve
is varied to allow for optimum control of the engine idling speed. The crankshaft position sensor (POS) detects
the actual engine speed and sends a signal to the ECM.
The ECM controls the electric throttle control actuator so that the engine speed coincides with the target value
memorized in the ECM. The target engine speed is the lowest speed at which the engine can operate steadly.
The optimum value stored in the ECM is determined by taking into consideration various engine conditions,
such as during warming up, deceleration, and engine load (air conditioner, power steering and cooling fan
operation, etc.).

On Board Diagnosis Logic

NHEC0798

DTC No.

Trouble diagnosis

name

DTC Detecting Condition

Possible Cause

P0507
0507

Idle speed control
system RPM higher
than expected

The idle speed is not in the specified range.

쐌

Electric throttle control actuator

쐌

Intake air leak

DTC Confirmation Procedure

NHEC0800

NOTE:

쐌

If

“DTC

Confirmation

Procedure”

has

been

previously

conducted, always turn ignition switch “OFF” and wait at least
10 seconds before conducting the next test.

쐌

If the target idle speed is out of the specified value, per-
form “Idle Air Volume Learning” before conducting “DTC
Confirmation Procedure”. For the target idle speed, refer
to the “Service Data and Specifications (SDS)”, EC-730.

TESTING CONDITION:

쐌

Before performing the following procedure, confirm that
battery voltage is more than 11V at idle.

쐌

Always perform the test at a temperature above −10°C
(14°F).

SEF174Y

WITH CONSULT-II

NHEC0800S03

1)

Open engine hood.

2)

Start engine and warm it up to normal operating temperature.

3)

Turn ignition switch “OFF” and wait at least 10 seconds.

4)

Turn ignition switch “ON” again and select “DATA MONITOR”
mode with CONSULT-II.

5)

Start engine and run it for at least 1 minute at idle speed.

6)

If 1st trip DTC is detected, go to “Diagnostic Procedure”,
EC-429.

DTC P0507 ISC SYSTEM

Description

EC-428

WITH GST

NHEC0800S04

Follow the procedure “With CONSULT-II” above.

Diagnostic Procedure

NHEC0802

1

CHECK INTAKE AIR LEAK

1. Start engine and let it idle.
2. Listen for an intake air leak after the mass air flow sensor.

OK or NG

OK

䊳

GO TO 2.

NG

䊳

Discover air leak location and repair.

2

REPLACE ECM

1. Stop engine.
2. Replace ECM.
3. Perform initialization of IVIS (NATS) system and registration of all IVIS (NATS) ignition key IDs. Refer to “IVIS (INFINITI

VEHICLE IMMOBILIZER SYSTEM — NATS)”, EC-90.

4. Perform “Accelerator Pedal Released Position Learning”, EC-71.
5. Perform “Throttle Valve Closed Position Learning”, EC-71.
6. Perform “Idle Air Volume Learning”, EC-71.

䊳

INSPECTION END

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DTC P0507 ISC SYSTEM

DTC Confirmation Procedure (Cont’d)

EC-429

SEC046D

Component Description

NHEC1250

Power steering pressure (PSP) sensor is installed to the power
steering high-pressure tube and detects a power steering load.
This sensor is a potentiometer which transforms the power steer-
ing load into output voltage, and emits the voltage signal to the
ECM. The ECM controls the electric throttle control actuator and
adjusts the throttle valve opening angle to increase the engine
speed and adjusts the idle speed for the increased load.

CONSULT-II Reference Value in Data Monitor
Mode

NHEC1256

Specification data are reference values.

MONITOR ITEM

CONDITION

SPECIFICATION

PW/ST SIGNAL

쐌

Engine: After warming up, idle the
engine

Steering wheel is in neutral position.
(Forward direction)

OFF

Steering wheel is turned.

ON

On Board Diagnosis Logic

NHEC1251

The MIL will not light up for this self-diagnosis.

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

P0550
0550

Power steering pressure
sensor circuit

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

쐌

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

쐌

Power steering pressure sensor

DTC Confirmation Procedure

NHEC1252

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.

Turn ignition switch “ON”.

2.

Select “DATA MONITOR” mode with CONSULT-II.

3.

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

4.

If 1st trip DTC is detected, go to EC-432, “Diagnostic Proce-
dure”.

With GST

Follow the procedure “WITH CONSULT-II” above.

DTC P0550 PSP SENSOR

Component Description

EC-430

Wiring Diagram

NHEC1253

MEC568D

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DTC P0550 PSP SENSOR

Wiring Diagram

EC-431

Specification data are reference values and are measured between each terminal and body ground.

CAUTION:

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

TER-

MINAL

NO.

WIRE

COLOR

ITEM

CONDITION

DATA (DC Voltage)

58

B

Sensor ground

[Engine is running]

쐌

Warm-up condition

쐌

Idle speed

Approximately 0V

89

G

Power steering pres-
sure sensor

[Engine is running]

쐌

Steering wheel is being turned.

0.5 - 4.0V

[Engine is running]

쐌

Steering wheel is not being turned.

0.4 - 0.8V

111

R

Sensor power supply

[Ignition switch “ON”]

Approximately 5V

Diagnostic Procedure

NHEC1254

1

RETIGHTEN GROUND SCREWS

1. Turn ignition switch “OFF”.
2. Loosen and retighten engine ground screws.

SEC047D

䊳

GO TO 2.

DTC P0550 PSP SENSOR

Wiring Diagram (Cont’d)

EC-432