Nissan Frontier. Manual — part 441

P0500 VSS

EC-335

< DTC/CIRCUIT DIAGNOSIS >

[QR25DE]

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EC

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Refer to

MWI-4, "Work Flow"

.

>> INSPECTION END

EC-336

< DTC/CIRCUIT DIAGNOSIS >

[QR25DE]

P0506 ISC SYSTEM

P0506 ISC SYSTEM

Description

INFOID:0000000009481004

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 steadily.

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

INFOID:0000000009481005

DTC Confirmation Procedure

INFOID:0000000009481006

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.

• If the target idle speed is out of the specified value, perform

EC-124, "Idle Air Volume Learning"

,

before conducting DTC Confirmation Procedure. For the target idle speed, refer to the

EC-471

.

TESTING CONDITION:

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

• Always perform the test at a temperature above

−10°C (14°F).

WITH CONSULT

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. Start engine and run it for at least 1 minute at idle speed.
5. Check 1st trip DTC.
6. If 1st trip DTC is detected, go to

EC-336, "Diagnosis Procedure"

.

WITH GST

Follow the procedure “WITH CONSULT” above.

Diagnosis Procedure

INFOID:0000000009481007

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

>> GO TO 2.

NG

>> Discover air leak location and repair.

2.

REPLACE ECM

1. Stop engine.

CAUTION:

Perform PROCEDURE AFTER REPLACING ECM. Refer to

EC-121, "Procedure After Replacing

ECM"

.

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

P0506
0506

Idle speed control system
RPM lower than expected

The idle speed is less than the target idle
speed by 100 rpm or more.

• Electric throttle control actuator
• Intake air leak

P0506 ISC SYSTEM

EC-337

< DTC/CIRCUIT DIAGNOSIS >

[QR25DE]

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2. Replace ECM.

>> INSPECTION END

EC-338

< DTC/CIRCUIT DIAGNOSIS >

[QR25DE]

P0507 ISC SYSTEM

P0507 ISC SYSTEM

Description

INFOID:0000000009481008

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 steadily.

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

INFOID:0000000009481009

DTC Confirmation Procedure

INFOID:0000000009481010

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.

• If the target idle speed is out of the specified value, perform

EC-124, "Idle Air Volume Learning"

,

before conducting DTC Confirmation Procedure. For the target idle speed, refer to the

EC-471

.

TESTING CONDITION:

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

• Always perform the test at a temperature above

−10°C (14°F).

WITH CONSULT

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. Start engine and run it for at least 1 minute at idle speed.
5. Check 1st trip DTC.
6. If 1st trip DTC is detected, go to

EC-338, "Diagnosis Procedure"

.

WITH GST

Follow the procedure “WITH CONSULT” above.

Diagnosis Procedure

INFOID:0000000009481011

1.

CHECK PCV HOSE CONNECTION

Confirm that PCV hose is connected correctly.
OK or NG

OK

>> GO TO 2.

NG

>> Repair or replace.

2.

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

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

P0507
0507

Idle speed control system
RPM higher than expected

The idle speed is more than the target idle
speed by 200 rpm or more.

• Electric throttle control actuator
• Intake air leak
• PCV system