idle problem

[shane85]

need help asap got an 03 2.5 altima that is idling at over 2000 rpm n fluctuates when the ac is turned off but as long as its in drive there is no problem drives normal neways im new to this any help would b gr8. i got a wicked altima gotta post some pics soon.

[Darius]

Is it running of the stock ECU or an aftermarket ECU or piggyback system?

Here is the verbage in the FSM about how idle is controlled:"The ECM controls the engine idle speed to a specified level through the fine adjustment of the air, which is letinto the intake manifold, by operating the electric throttle control actuator. The operating of the throttle valve isvaried to allow for optimum control of the engine idling speed. The crankshaft position sensor (POS) detectsthe 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 valuememorized 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 fanoperation, etc.)."

It then lists possible causes in a table on page EC-424 as being:1) Electric throttle control actuator2) Intake air leak3) PCV system

Keep us posted.

[deebsr6]

here are some things you can try

Accelerator Pedal Released Position Learning EBS00CC4DESCRIPTION“Accelerator Pedal Released Position Learning” is an operation to learn the fully released position of the acceleratorpedal by monitoring the accelerator pedal position sensor output signal. It must be performed each timeharness connector of accelerator pedal position sensor or ECM is disconnected.OPERATION PROCEDURE1. 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 EBS00CC3DESCRIPTION“Throttle Valve Closed Position Learning” is an operation to learn the fully closed position of the throttle valveby monitoring the throttle position sensor output signal. It must be performed each time harness connector of the electric throttle control actuator or ECM is disconnected.OPERATION PROCEDURE1. 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 EBS00CC5Pre-conditioning:For A/T models without CONSULT-II and M/T models, drive vehicle for 10 minutes.DESCRIPTION1. Perform "Accelerator Pedal Released Position Learning" .2. Perform "Throttle Valve Closed Position Learning" .3. Start engine and warm it up to normal operating temperature.4. Check that all items listed under the topic “PRE-CONDITIONING” (previously mentioned) are in good order.5. Turn ignition switch “OFF” and wait at least 10 seconds.6. Confirm that accelerator pedal is fully released, turn ignition switch “ON” and wait 3 seconds.7. Repeat the following procedure quickly five times within 5 seconds.a. Fully depress the accelerator pedal.b. Fully release the accelerator pedal.8. Wait 7 seconds, fully depress the accelerator pedal and keep it for approx. 20 seconds until the MIL stopsblinking and turned ON.9. Fully release the accelerator pedal within 3 seconds after the MIL goes off.

hope this helps

P.S. post up some pics

[Darius]

I'm also thinking that since the speed of the engine is entirely monitored by the crank angle sensor the ECU maybe functioning properly but receiving a false signal from the CAS. Those have a recall on them for some QR25 production years so that's why I don't rule that out either.

If deebsr6's ECU reset procedures don't help, then refer to my previous post. Work from cheapest to most expensive (Intake air leak, PCV system, CAS, and Elec TB)

Please keep us posted so we have a record of your well-described symptom and what the cause of it was. And for sure post pics!!

[showtimesaltima]

need help asap got an 03 2.5 altima that is idling at over 2000 rpm n fluctuates when the ac is turned off but as long as its in drive there is no problem drives normal neways im new to this any help would b gr8. i got a wicked altima gotta post some pics soon.

the only time that happened to me was when i was cleaning the throttle body i didnt put back the cold air intake on correctly and my car was idling at 2500 rpms and wouldnt go past 4000. you might have a leak like they said but please let us i know . i like learning these things