Nissan Sentra. Manual — part 409

EC-332

< DTC/CIRCUIT DIAGNOSIS >

[MRA8DE]

P0500 VSS

YES

>> GO TO 2.

NO

>> GO TO 5.

2.

PRECONDITIONING

If DTC Confirmation Procedure has been previously conducted, always perform the following procedure

before conducting 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.

>> GO TO 3.

3.

CHECK VEHICLE SPEED SIGNAL

NOTE:

This procedure 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.

With CONSULT

1. Start engine.

2. Read “VHCL SPEED SE” in “DATA MONITOR” mode of “ENGINE” using CONSULT. The vehicle speed

on CONSULT should exceed 10 km/h (6 mph) when rotating wheels with suitable gear position.

Is the inspection result normal?

YES

>> GO TO 4.

NO

>> Proceed to

EC-333, "M/T MODELS : Diagnosis Procedure"

.

4.

PERFORM DTC CONFIRMATION PROCEDURE

1. Select “DATA MONITOR” mode of “ENGINE” using CONSULT.

2. Warm engine up to normal operating temperature.

3. Maintain the following conditions for at least 50 consecutive seconds.

CAUTION:

Always drive vehicle at a safe speed.

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

YES

>> Proceed to

EC-333, "M/T MODELS : Diagnosis Procedure"

.

NO

>> INSPECTION END

5.

PERFORM COMPONENT FUNCTION CHECK

Perform component function check. Refer to

EC-332, "M/T MODELS : Component Function Check"

.

Use component function check to check the overall function of the vehicle speed signal circuit. During this

check, a 1st trip DTC might not be confirmed.
Is the inspection result normal?

YES

>> INSPECTION END

NO

>> Proceed to

EC-333, "M/T MODELS : Diagnosis Procedure"

.

M/T MODELS : Component Function Check

INFOID:0000000009758572

1.

PERFORM COMPONENT FUNCTION CHECK

With GST

1. Lift up drive wheels.

2. Start engine.

3. Read vehicle speed signal in Service $01 with GST.

ENG SPEED

2,100 - 6,000 rpm

COOLANT TEMP/S

More than 70

°C (158°F)

B/FUEL SCHDL

4.0 - 19.0 msec

Selector lever

Except Neutral position

PW/ST SIGNAL

OFF

P0500 VSS

EC-333

< DTC/CIRCUIT DIAGNOSIS >

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The vehicle speed signal on GST should be able to exceed 10 km/h (6 MPH) when rotating wheels with

suitable gear position.

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> Proceed to

EC-333, "M/T MODELS : Diagnosis Procedure"

.

M/T MODELS : Diagnosis Procedure

INFOID:0000000009758573

1.

CHECK DTC WITH ABS ACTUATOR AND ELECTRIC UNIT (CONTROL UNIT)

Check DTC with ABS actuator and electric unit (control unit). Refer to

BRC-31, "CONSULT Function (ABS)"

.

Is the inspection result normal?

YES

>> GO TO 2.

NO

>> Perform trouble shooting relevant to DTC indicated. Refer to

BRC-43, "DTC Index"

.

2.

CHECK DTC WITH COMBINATION METER

Check DTC with combination meter. Refer to

MWI-17, "CONSULT Function (METER/M&A)"

.

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> Perform trouble shooting relevant to DTC indicated. Refer to

MWI-26, "DTC Index"

.

EC-334

< DTC/CIRCUIT DIAGNOSIS >

[MRA8DE]

P0506 ISC SYSTEM

P0506 ISC SYSTEM

Description

INFOID:0000000009758574

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.).

DTC Logic

INFOID:0000000009758575

DTC DETECTION LOGIC

NOTE:

If DTC P0506 is displayed with other DTC, first perform the trouble diagnosis for the other DTC.

DTC CONFIRMATION PROCEDURE

1.

PRECONDITIONING

If DTC Confirmation Procedure has been previously conducted, always perform the following procedure

before conducting 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.

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

EC-140, "Work Procedure"

, before con-

ducting DTC Confirmation Procedure.

TESTING CONDITION:

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

• Always perform the test at a temperature above

−10°C (14°F).

>> GO TO 2.

2.

PERFORM DTC CONFIRMATION PROCEDURE

1. Start engine and warm it up to normal operating temperature.

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

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

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

YES

>> Proceed to

EC-334, "Diagnosis Procedure"

.

NO

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000009758576

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.
Is intake air leak detected?

YES

>> Discover air leak location and repair.

DTC No.

CONSULT screen terms

(Trouble diagnosis content)

DTC detecting condition

Possible cause

P0506

ISC SYSTEM
(Idle air 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-335

< DTC/CIRCUIT DIAGNOSIS >

[MRA8DE]

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NO

>> Replace ECM. Refer to

EC-485, "Removal and Installation"

.