Nissan Sentra. Manual - part 361

EC-140

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IDLE AIR VOLUME LEARNING

IDLE AIR VOLUME LEARNING

Description

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Idle Air Volume Learning is a function of ECM to learn the idle air volume that keeps each engine idle speed

within the specific range. It must be performed under any of the following conditions:

• Each time electric throttle control actuator or ECM is replaced.

• Idle speed or ignition timing is out of specification.

Work Procedure

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1.

PRECONDITIONING

Make sure that all of the following conditions are satisfied.

Learning will be cancelled if any of the following conditions are missed for even a moment.

• Battery voltage: More than 11.6 V (At idle)

• Engine coolant temperature: 70 - 100

°C (158 - 212°F)

• Selector lever: P or N (CVT), Neutral (M/T)

• Electric load switch: OFF

(Air conditioner, headlamp, rear window defogger)

On vehicles equipped with daytime running light systems, set lighting switch to the 1st position to

light only small lamps.

• Steering wheel: Neutral (Straight-ahead position)

• Vehicle speed: Stopped

• Transmission: Warmed-up

- CVT models

• With CONSULT: Drive vehicle until “ATF TENP SEN” in “DATA MONITOR” mode of “CVT” system indicates

less than 0.9 V.

• Without CONSULT: Drive vehicle for 10 minutes.

- M/T models

• Drive vehicle for 10 minutes.
Do you have CONSULT?

YES

>> GO TO 2.

NO

>> GO TO 3.

2.

IDLE AIR VOLUME LEARNING

With CONSULT

1. Perform Accelerator Pedal Released Position Learning. Refer to 

EC-138, "Work Procedure"

.

2. Perform Throttle Valve Closed Position Learning. Refer to 

EC-139, "Work Procedure"

.

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

4. Select “IDLE AIR VOL LEARN” in “WORK SUPPORT” mode of “ENGINE”.

5. Touch “START” and wait 20 seconds.
Is “CMPLT” displayed on CONSULT screen?

YES

>> GO TO 4.

NO

>> GO TO 5.

3.

IDLE AIR VOLUME LEARNING

Without CONSULT

NOTE:

• It is better to count the time accurately with a clock.

• It is impossible to switch the diagnostic mode when an accelerator pedal position sensor circuit has

a malfunction.

1. Perform Accelerator Pedal Released Position Learning. Refer to 

EC-138, "Work Procedure"

.

2. Perform Throttle Valve Closed Position Learning. Refer to 

EC-139, "Work Procedure"

.

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

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

5. Confirm that accelerator pedal is fully released, turn ignition switch ON and wait 3 seconds.

6. Repeat the following procedure quickly five times within 5 seconds.

-

Fully depress the accelerator pedal.

-

Fully release the accelerator pedal.

IDLE AIR VOLUME LEARNING

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7. Wait 7 seconds, fully depress the accelerator pedal and keep it for approximately 20 seconds until the MIL

stops blinking and turned ON.

8. Fully release the accelerator pedal within 3 seconds after the MIL turned ON.

9. Start engine and let it idle.

10. Wait 20 seconds.

>> GO TO 4

4.

CHECK IDLE SPEED AND IGNITION TIMING

Rev up the engine two or three times and make sure that idle speed and ignition timing are within the specifi-

cations. For specification, refer to 

EC-486, "Idle Speed"

 and 

EC-486, "Ignition Timing"

.

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> GO TO 5.

5.

DETECT MALFUNCTIONING PART

Check the following

• Check that throttle valve is fully closed.

• Check PCV valve operation.

• Check that downstream of throttle valve is free from air leakage.
Is the inspection result normal?

YES

>> GO TO 6.

NO

>> Repair or replace malfunctioning part.

6.

DETECT MALFUNCTIONING PART

Engine component parts and their installation condition are questionable. Check and eliminate the cause of

the incident.

It is useful to perform “TROUBLE DIAGNOSIS - SPECIFICATION VALUE”. Refer to 

EC-157, "Description"

.

If any of the following conditions occur after the engine has started, eliminate the cause of the incident and

perform Idle Air Volume Learning all over again:

• Engine stalls.

• Erroneous idle.

>> INSPECTION END

SEC897C

EC-142

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MIXTURE RATIO SELF-LEARNING VALUE CLEAR

MIXTURE RATIO SELF-LEARNING VALUE CLEAR

Description

INFOID:0000000009758409

This describes how to erase the mixture ratio self-learning value. For the actual procedure, follow the instruc-

tions in “Diagnosis Procedure”.

Work Procedure

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1.

START

With CONSULT

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

2. Select “SELF-LEARNING CONT” in “WORK SUPPORT” mode of “ENGINE” using CONSULT.

3. Clear mixture ratio self-learning value by touching “CLEAR”.

With GST

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

2. Turn ignition switch OFF.

3. Disconnect mass air flow sensor harness connector.

4. Restart engine and let it idle for at least 5 seconds.

5. Stop engine and reconnect mass air flow sensor harness connector.

6. Select Service $03 with GST. Make sure DTC P0102 is detected.

7. Select Service $04 with GST to erase the DTC P0102.

>> END

FUEL PRESSURE

EC-143

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FUEL PRESSURE

Work Procedure

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FUEL PRESSURE RELEASE

1.

FUEL PRESSURE RELEASE

With CONSULT

1. Turn ignition switch ON.

2. Perform “FUEL PRESSURE RELEASE” in “WORK SUPPORT” mode of “ENGINE” using CONSULT.

3. Start engine.

4. After engine stalls, crank it two or three times to release all fuel pressure.

5. Turn ignition switch OFF.

Without CONSULT

1. Remove fuel pump fuse located in IPDM E/R.

2. Start engine.

3. After engine stalls, crank it two or three times to release all fuel pressure.

4. Turn ignition switch OFF.

5. Reinstall fuel pump fuse after servicing fuel system.

>> END

FUEL PRESSURE CHECK

CAUTION:

• Before disconnecting fuel line, release fuel pressure from fuel line to eliminate danger.

• The fuel hose connection method used when taking fuel pressure check must not be used for other

purposes.

• Be careful not to scratch or put debris around connection area when servicing, so that the quick

connector maintains sealability with O-rings inside.

• Do not perform fuel pressure check with electrical systems operating (i.e. lights, rear defogger, A/C,

etc.) Fuel pressure gauge may indicate false readings due to varying engine load and changes in

manifold vacuum.

NOTE:

Prepare pans or saucers under the disconnected fuel line because the fuel may spill out. The fuel pres-

sure cannot be completely released because this models do not have fuel return system.

1.

FUEL PRESSURE CHECK

1. Release fuel pressure to zero.

2. Prepare fuel hose for fuel pressure check (B) and fuel tube

adapter [SST: KV1011840] (D), then connect fuel pressure

gauge (A).

CAUTION:

• Use suitable fuel hose for fuel pressure check (genuine

NISSAN fuel hose without quick connector).

• To avoid unnecessary force or tension to hose, use mod-

erately long fuel hose for fuel pressure check.

• Do not use the fuel hose for checking fuel pressure with damage or cracks on it.

• Use Pressure Gauge to check fuel pressure.

3. Remove fuel hose.

CAUTION:

Do not twist or kink fuel hose because it is plastic hose.

: To quick connector

: To fuel tube

C

:  Clamp

PBIB2982E