Nissan Altima (L32) 2007-2012 Service Manual: Idle air volume learning

 Description

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.

 Special Repair Requirement

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 12.9V (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 light systems, if the parking brake is applied before the engine is started the headlamp will not be illuminated.

• Steering wheel: Neutral (Straight-ahead position) • Vehicle speed: Stopped

• Transmission: Warmed-up

- CVT models

• With CONSULT-III: Drive vehicle until “ATF TEMP SEN” in “DATA MONITOR” mode of “CVT” system indicates less than 0.9V.

• Without CONSULT-III: Drive vehicle for 10 minutes.

- M/T models

• Drive vehicle for 10 minutes.

Do you have CONSULT-III? YES >> GO TO 2.

NO >> GO TO 3.

2.IDLE AIR VOLUME LEARNING

1. Perform Accelerator Pedal Released Position Learning. Refer to EC-29, "ACCELERATOR PEDAL RELEASED POSITION LEARNING : Special Repair Requirement".

2. Perform Throttle Valve Closed Position Learning. Refer to EC-29, "THROTTLE VALVE CLOSED POSITION LEARNING : Special Repair Requirement".

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

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

5. Touch “START” and wait 20 seconds.

Is “CMPLT” displayed on CONSULT-III screen? YES >> GO TO 4.

NO >> GO TO 5.

3.IDLE AIR VOLUME LEARNING

Without CONSULT-III

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-29, "ACCELERATOR PEDAL RELEASED POSITION LEARNING : Special Repair Requirement".

2. Perform Throttle Valve Closed Position Learning. Refer to EC-29, "THROTTLE VALVE CLOSED POSITION LEARNING : Special Repair Requirement".

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.

7. Wait 7 seconds, fully depress the accelerator pedal and keep it for approx. 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 specifications.

Is the inspection result normal? YES >> INSPECTION END

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-136, "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