Nissan Altima L32. Manual - part 568

P1225 TP SENSOR

EC-1393

< COMPONENT DIAGNOSIS >

[VQ35DE]

C

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EC

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3. Check if foreign matter is caught between the throttle valve (1)

and the housing.

-

Electric throttle control actuator (2)

-

: Vehicle front

Is the inspection result normal?

YES

>> GO TO 2.

NO

>> Remove the foreign matter and clean the electric throttle

control actuator inside.

2.

REPLACE ELECTRIC THROTTLE CONTROL ACTUATOR

1. Replace electric throttle control actuator.

2. Go to 

EC-1393, "Special Repair Requirement"

.

>> INSPECTION END

Special Repair Requirement

INFOID:0000000004362248

1.

PERFORM THROTTLE VALVE CLOSED POSITION LEARNING

Refer to 

EC-1053, "THROTTLE VALVE CLOSED POSITION LEARNING : Special Repair Requirement"

>> GO TO 2.

2.

PERFORM IDLE AIR VOLUME LEARNING

Refer to 

EC-1053, "IDLE AIR VOLUME LEARNING : Special Repair Requirement"

>> END

ALBIA0124ZZ

EC-1394

< COMPONENT DIAGNOSIS >

[VQ35DE]

P1226 TP SENSOR

P1226 TP SENSOR

Description

INFOID:0000000004362249

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 two sensors. These sensors are a

kind of potentiometer which transform the throttle valve position into

output voltage, and emit the voltage signals to the ECM. The ECM

judges the current opening angle of the throttle valve from these sig-

nals and controls the throttle valve opening angle in response to

driving conditions via the throttle control motor.

DTC Logic

INFOID:0000000004362250

DTC DETECTION LOGIC

DTC CONFIRMATION PROCEDURE

1.

PRECONDITIONING

If DTC Confirmation Procedure has been previously conducted, always perform the following before conduct-

ing the next test.

1. Turn ignition switch OFF and wait at least 10 seconds.

2. Turn ignition switch ON.

3. Turn ignition switch OFF and wait at least 10 seconds.

TESTING CONDITION:

Before performing the following procedure, confirm that battery voltage is more than 10 V at idle.

>> GO TO 2.

2.

PERFORM DTC CONFIRMATION PROCEDURE

1. Turn ignition switch ON.

2. Turn ignition switch OFF and wait at least 10 seconds.

3. Turn ignition switch ON.

4. Repeat steps 2 and 3 for 32 times.

5. Check 1st trip DTC.
Is 1st trip DTC detected?

YES

>> Go to 

EC-1394, "Diagnosis Procedure"

.

NO

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000004362251

1.

CHECK ELECTRIC THROTTLE CONTROL ACTUATOR VISUALLY

1. Turn ignition switch OFF.

2. Remove the intake air duct.

PBIB0145E

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

P1226

Closed throttle position 
learning performance

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

• Electric throttle control actuator

(TP sensor 1 and 2)

P1226 TP SENSOR

EC-1395

< COMPONENT DIAGNOSIS >

[VQ35DE]

C

D

E

F

G

H

I

J

K

L

M

A

EC

N

P

O

3. Check if foreign matter is caught between the throttle valve (1)

and the housing.

-

Electric throttle control actuator (2)

-

: Vehicle front

Is the inspection result normal?

YES

>> GO TO 2.

NO

>> Remove the foreign matter and clean the electric throttle

control actuator inside.

2.

REPLACE ELECTRIC THROTTLE CONTROL ACTUATOR

1. Replace electric throttle control actuator.

2. Go to 

EC-1393, "Special Repair Requirement"

.

>> INSPECTION END

Special Repair Requirement

INFOID:0000000004362252

1.

PERFORM THROTTLE VALVE CLOSED POSITION LEARNING

Refer to 

EC-1053, "THROTTLE VALVE CLOSED POSITION LEARNING : Special Repair Requirement"

>> GO TO 2.

2.

PERFORM IDLE AIR VOLUME LEARNING

Refer to 

EC-1053, "IDLE AIR VOLUME LEARNING : Special Repair Requirement"

>> END

ALBIA0124ZZ

EC-1396

< COMPONENT DIAGNOSIS >

[VQ35DE]

P1421 COLD START CONTROL

P1421 COLD START CONTROL

Description

INFOID:0000000004362253

ECM controls ignition timing and engine idle speed when engine is started with pre-warming up condition.

This control promotes the activation of three way catalyst by heating the catalyst and reduces emissions.

DTC Logic

INFOID:0000000004362254

DTC DETECTION LOGIC

NOTE:

• If DTC P1421 is displayed with other DTC, first perform the trouble diagnosis for other DTC.

DTC CONFIRMATION PROCEDURE

1.

PRECONDITIONING

If DTC Confirmation Procedure has been previously conducted, always perform the following before conduct-

ing the next test.

1. Turn ignition switch OFF and wait at least 10 seconds.

2. Turn ignition switch ON.

3. Turn ignition switch OFF and wait at least 10 seconds.

TESTING CONDITION:

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

>> GO TO 2.

2.

PERFORM DTC CONFIRMATION PROCEDURE

With CONSULT-III

1. Turn ignition switch ON.

2. Select “DATA MONITOR” mode with CONSULT-III.

3. Check that the “COOLAN TEMP/S” indication is between 4

°C (39°F) and 36°C (97°F).

If “COOLAN TEMP/S” indication is within the specified value, go to the following steps.

If “COOLAN TEMP/S” indication is out of the specified value, cool engine down or warm engine up and go

to step 1.

4. Start engine and let it idle for 5 minutes.

5. Check 1st trip DTC.

With GST

Follow the procedure “With CONSULT-III” above.
Is 1st trip DTC detected?

YES

>> Go to 

EC-1396, "Diagnosis Procedure"

.

NO

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000004362255

1.

PERFORM IDLE AIR VOLUME LEARNING

Perform 

EC-1053, "IDLE AIR VOLUME LEARNING : Special Repair Requirement"

.

Is Idle Air Volume Learning carried out successfully?

YES

>> GO TO 2.

NO

>> Follow the instruction of Idle Air Volume Learning.

2.

CHECK INTAKE SYSTEM

Check for the cause of intake air volume lacking. Refer to the following.

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

P1421

Cold start emission reduction 
strategy monitoring

ECM does not control ignition timing and engine 
idle speed properly when engine is started with 
pre-warming up condition.

• Lack of intake air volume
• Fuel injection system
• ECM