Infiniti Q45. Manual - part 476

DTC P1225 TP SENSOR

EC-543

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Diagnostic Procedure

NBS00229

1. 

CHECK ELECTRIC THROTTLE CONTROL ACTUATOR VISUALLY

1.

Turn ignition switch OFF.

2.

Remove the intake air duct.

3.

Check if foreign matter is caught between the throttle valve and
the housing.

OK or NG

OK

>> GO TO 2.

NG

>> Remove the foreign matter and clean the electric throttle

control actuator inside.

2. 

REPLACE ELECTRIC THROTTLE CONTROL ACTUATOR

1.

Replace the electric throttle control actuator.

2.

Perform 

EC-78, "Throttle Valve Closed Position Learning"

 .

3.

Perform 

EC-78, "Idle Air Volume Learning"

 .

>> INSPECTION END

Removal and Installation

NBS0022A

ELECTRIC THROTTLE CONTROL ACTUATOR

Refer to 

EM-19, "INTAKE MANIFOLD"

 .

PBIB2439E

EC-544

DTC P1226 TP SENSOR

DTC P1226 TP SENSOR

PFP:16119

Component Description

NBS0022B

Electric throttle control actuator consists of throttle control motor,
throttle position sensor, etc. The throttle position sensor responds to
the throttle valve movement. 
The throttle position sensor has the two sensors. These sensors are
a kind of potentiometers which transform the throttle valve position
into output voltage, and emit the voltage signal to the ECM. In addi-
tion, these sensors detect the opening and closing speed of the
throttle valve and feed the voltage signals to the ECM. The ECM
judges the current opening angle of the throttle valve from these sig-
nals and the ECM controls the throttle control motor to make the
throttle valve opening angle properly in response to driving condi-
tion.

On Board Diagnosis Logic

NBS0022C

The MIL will not light up for this diagnosis.

DTC Confirmation Procedure

NBS0022D

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 battery voltage is more than 10V at idle.

 WITH CONSULT-II

1.

Turn ignition switch ON.

2.

Select “DATA MONITOR” mode with CONSULT-II.

3.

Turn ignition switch OFF, wait at least 10 seconds.

4.

Turn ignition switch ON.

5.

Repeat steps 3 and 4 for 32 times.

6.

If 1st trip DTC is detected, go to 

EC-545, "Diagnostic Procedure"

.

 WITH GST

Follow the procedure “WITH CONSULT-II” above.

PBIB0145E

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

P1226
1226

Closed throttle position 
learning performance

Closed throttle position learning is not per-
formed successfully, repeatedly.

●

Electric throttle control actuator
(TP sensor 1 and 2)

SEF058Y

DTC P1226 TP SENSOR

EC-545

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Diagnostic Procedure

NBS0022E

1. 

CHECK ELECTRIC THROTTLE CONTROL ACTUATOR VISUALLY

1.

Turn ignition switch OFF.

2.

Remove the intake air duct.

3.

Check if foreign matter is caught between the throttle valve and
the housing.

OK or NG

OK

>> GO TO 2.

NG

>> Remove the foreign matter and clean the electric throttle

control actuator inside.

2. 

REPLACE ELECTRIC THROTTLE CONTROL ACTUATOR

1.

Replace the electric throttle control actuator.

2.

Perform 

EC-78, "Throttle Valve Closed Position Learning"

 .

3.

Perform 

EC-78, "Idle Air Volume Learning"

 .

>> INSPECTION END

Removal and Installation

NBS0022F

ELECTRIC THROTTLE CONTROL ACTUATOR

Refer to 

EM-19, "INTAKE MANIFOLD"

 .

PBIB2439E

EC-546

DTC P1442 EVAP CONTROL SYSTEM

DTC P1442 EVAP CONTROL SYSTEM

PFP:14950

On Board Diagnosis Logic

NBS0022K

NOTE:
If DTC P1442 is displayed with P0447, perform trouble diagnosis for DTC P0447 first. (See 

EC-419

 .)

This diagnosis detects leaks in the EVAP purge line using vapor pressure in the fuel tank.
The EVAP canister vent control valve is closed to shut the EVAP purge line. The vacuum cut valve bypass
valve will then be opened to clear the line between the fuel tank and the EVAP canister purge volume control
solenoid valve. The EVAP control system pressure sensor can now monitor the pressure inside the fuel tank.
If pressure increases, the ECM will check for leaks in the line between the vacuum cut valve and EVAP canis-
ter purge volume control solenoid valve.

CAUTION:

●

Use only a genuine NISSAN fuel filler cap as a replacement. If an incorrect fuel filler cap is used,
the MIL may come on.

●

If the fuel filler cap is not tightened properly, the MIL may come on.

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

P1442
1442

EVAP control system 
small leak detected 
(positive pressure)

EVAP control system has a leak, EVAP 
control system does not operate prop-
erly.

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Incorrect fuel tank vacuum relief valve

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Incorrect fuel filler cap used

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Fuel filler cap remains open or fails to close.

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Foreign matter caught in fuel filler cap.

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Leak is in line between intake manifold and 
EVAP canister purge volume control solenoid 
valve.

●

Foreign matter caught in EVAP canister vent 
control valve.

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EVAP canister or fuel tank leaks

●

EVAP purge line (pipe and rubber tube) leaks

●

EVAP purge line rubber tube bent

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Blocked or bent rubber tube to EVAP control sys-
tem pressure sensor

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Loose or disconnected rubber tube

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EVAP canister vent control valve and the circuit

●

EVAP canister purge volume control solenoid 
valve and the circuit

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Fuel tank temperature sensor

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O-ring of EVAP canister vent control valve is 
missing or damaged

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Water separator

●

EVAP canister is saturated with water

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EVAP control system pressure sensor

●

Fuel level sensor and the circuit

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Refueling control valve

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ORVR system leaks

SEF323U