2.5l. Why does it idle up and down? - 2003 Nissan Altima

SOURCE: 2003 Nissan Altima?

Where is the sensor placed on the car?

SOURCE: 2003 Nissan altima alternator

how do yow remuve alternaotor on a 2003 nissan altima

SOURCE: 2003 nissan altima rpm goes

I have also read in the service manual that doing an idle relearn helps with RPM problems. This is the procedure below. It is complicated to do unless you have a watch or something to count the seconds with.

DESCRIPTION
“Accelerator Pedal Released Position Learning” is an operation to learn the fully released position of the accelerator
pedal by monitoring the accelerator pedal position sensor output signal. It must be performed each time
harness connector of accelerator pedal position sensor or ECM is disconnected.
OPERATION PROCEDURE
1. Make sure that accelerator pedal is fully released.
2. Turn ignition switch “ON” and wait at least 2 seconds.
3. Turn ignition switch “OFF” wait at least 10 seconds.
4. Turn ignition switch “ON” and wait at least 2 seconds.
5. Turn ignition switch “OFF” wait at least 10 seconds.
Throttle Valve Closed Position Learning UBS002OA
DESCRIPTION
“Throttle Valve Closed Position Learning” is an operation to learn the fully closed position of the throttle valve
by monitoring the throttle position sensor output signal. It must be performed each time harness connector of
electric throttle control actuator or ECM is disconnected.
OPERATION PROCEDURE
1. Make sure that accelerator pedal is fully released.
2. Turn ignition switch “ON”.
3. Turn ignition switch “OFF” wait at least 10 seconds.
Make sure that throttle valve moves during above 10 seconds by confirming the operating sound.
Idle Air Volume Learning UBS002OB
DESCRIPTION
“Idle Air Volume Learning” is an operation to learn the idle air volume that keeps each engine 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.
PREPARATION
Before performing “Idle Air Volume Learning”, 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 - 95ｰC (158 - 203ｰF)

PNP switch: ON

Electric load switch: OFF
(Air conditioner, headlamp, rear window defogger)
On vehicles equipped with daytime light systems, set lighting switch to the 1st position to light
only small lamps.

Steering wheel: Neutral (Straight-ahead position)

Vehicle speed: Stopped

SOURCE: crankshaft and camshaft sensors location in nissan altima 2003

You are incorrect sir. There is a very good Youtube video showing you exactly where it is that is how I changed mine. The Crankshaft is located behind the engine block below and around from the cam sensor which is easly spotted looking at the engine. The crankshaft is in a difficult spot but once you figure out where it is it's easy...ish hope this helps

SOURCE: the idle is too high at 1500 rpm on my 2003 nissan altima 2.5

yes turn down too around 900