05 Pathfinder 24K milesCleaned my throttle body last night (wow, the carbon!) and now my truck idles a tad higher and the service engine soon light is on....Took it to an Auto parts store that checks out the code and it came out "high idle".The parts guy says I must of popped off a vacuum line somewhere but I think the throttle body was so clogged up that its breathing like new again.The side of the air box does have a tube just dangling there that I've never seen before (anyone with an 05'ish Pathfinder verify this?)Anyone have this problem with there truck? Thanks!

This problem is perfectly normal after cleaning/replacing the throttle body. Over time as your throttle body collects carbon the air volume which passes through it changes very slightly. This slight change in air volume is registered by the ECU and the ECU will auto-correct itself over time so that the driver notices no difference in idling or throttle response.

When you cleaned the throttle body you increased the air volume which can pass through the throttle body and this confused the ECU into thinking that there is something wrong with the engine, causing the malfunction indicator lamp to illuminate.

There are some steps which you can take to remedy this problem, all of which are free and can be done in your driveway. The following tasks need to be performed in the following order:

1. Reset ECU

2. Accelerator Pedal Released Position Learning

3. Throttle Valve Closed Position Learning

4. Idle Air Volume Learning

---------------------------------------------------------- RESET ECU -----(The easy method below is much easier than this one, I suggest trying that one first)

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

2. Repeat the following steps (2a and 2b) procedures quickly five times within 5 seconds.

2-a. Fully depress the accelerator pedal (HARD). 2-b. Fully release the accelerator pedal.

3. Wait 7 seconds, fully depress the accelerator pedal and keep it for approx. 10 seconds until the CEL starts blinking.

4. Fully release the accelerator pedal (while the CEL is still blinking).

5. Wait about 10 seconds.

6. Fully depress the accelerator pedal and keep it for more than 10 seconds.

7. Fully release the accelerator pedal (The CEL light will continue to blink).

8. Turn ignition switch to “OFF” position and now you can start the car. The CEL light should be gone.

If the CEL light continues to remain ON, repeat the above steps. Timing is EXTREMELY critical to resetting the ECU.

----- EASY METHOD TO RESET ECU -----

1. Ignition "ON", count to 3.

2. Depress/Release pedal 5 times...hard and fast.

3. Count to 10 (not 7!) and fully depress pedal

4. Count to 12 (SES should be blinking), release pedal

5. Count to 10, depress pedal

6. Count to 10, release pedal.

7. Turn off ignition, then start engine. Done!

----- ACCELERATOR PEDAL RELEASED POSITION LEARNING -----

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 ----- 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 -----(The following steps are very time critical and any errors in timing may cause the malfunction indicator lamp to illuminate. If this occurs, you need to reset the ECU and complete all of the tasks again)

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

2. Check that all items listed under the topic PREPARATION (previously mentioned) are in good order.

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

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

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

5-a. Fully depress the accelerator pedal. 5-b. Fully release the accelerator pedal.

6. Wait 7 seconds, fully depress the accelerator pedal and keep it for approx. 20 seconds until the MIL stops blinking and turned ON.

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

8. Start engine and let it idle.

9. Wait 20 seconds.

12. Rev up the engine two or three times and make sure that idle speed and ignition timing are within the specifications. The vehicle should idle at 625 RPM's.

-----------------------------------------------------

Let me know if this works for you!


Modified by Pwnin O'Brien at 11:10 AM 8/29/2009

Why go through the whole pain in the a** ordeal like that one (even the "easy" one...) when you can just disconnect the negative battery cable and give it a couple minutes, hook it back up, presto-chango, ecu reset. Or does it not work in the '05s? Works in mine every time something gets a little off.

That is another option, but the negative cable must remain disconnected from the battery for about 24 hours to completely reset the ECU. Of course, after the ECU is reset, you still must complete the other three (Accelerator Pedal Released Position Learning, Throttle valve closed position learning, Idle Air Volume Learning).

From 2005 FSM:


Modified by Pwnin O'Brien at 11:45 AM 8/18/2009

Filled the tank up with premium and went for a long drive....Just like you said it must of corrected it's self.... No more light!Because of all the electronics a new car has, I heard it's not good to disconnect the battery to clear codes.Still concerned about that tubeThanks

Pwnin O’Brien wrote:This problem is perfectly normal after cleaning/replacing the throttle body. Over time as your throttle body collects carbon the air volume which passes through it changes very slightly. This slight change in air volume is registered by the ECU and the ECU will auto-correct itself over time so that the driver notices no difference in idling or throttle response.

When you cleaned the throttle body you increased the air volume which can pass through the throttle body and this confused the ECU into thinking that there is something wrong with the engine, causing the malfunction indicator lamp to illuminate.

Spoke too soon Light came back on Gonna try tonight to clear it all up

wizeguy wrote:Filled the tank up with premium and went for a long drive....Just like you said it must of corrected it's self.... No more light!Because of all the electronics a new car has, I heard it's not good to disconnect the battery to clear codes.Still concerned about that tubeThanks

Done! "crossing fingers"Light is off but idle seems a bit high....going to leave it alone unless the light comes back on

Did you ensure that before you started the idle air volume learning that the engine was warmed up to normal operating temperature? This is very crucial to getting the proper idle RPM's. When you do the idle air volume relearning the RPM's start out high and will then slow down to about 750RPM's. Your vehicle should idle around 750 RPM's (+/- 50 RPM's). If it does not (and the vehicle is at normal operating temperature) then I suggest redoing all of the procedures.

Yeah I drove it around for a while before resetting it all....What scares me is the morning start up....When I first start the motor, it jumps a tad over 2000 rpm then comes down to around 1000 rpm immediately.After it warms up the motor idles about 850-900 rpms.I think I'll redo it again...The "dry" start up scares me.Thanks!

Pwnin O’Brien wrote:Did you ensure that before you started the idle air volume learning that the engine was warmed up to normal operating temperature? This is very crucial to getting the proper idle RPM's. When you do the idle air volume relearning the RPM's start out high and will then slow down to about 750RPM's. Your vehicle should idle around 750 RPM's (+/- 50 RPM's). If it does not (and the vehicle is at normal operating temperature) then I suggest redoing all of the procedures.

Yeah, that's unusually high even after cleaning the throttle body. Do you remember the code number that the guy at the auto parts store read from your ECU when you started having the problem? Also, before you cleaned the throttle body and started having the issue, what was your normal idle after the engine was warmed up?

All he said was "high idle code" Before cleaning it was normal 750'ish

Pwnin O’Brien wrote:Yeah, that's unusually high even after cleaning the throttle body. Do you remember the code number that the guy at the auto parts store read from your ECU when you started having the problem? Also, before you cleaned the throttle body and started having the issue, what was your normal idle after the engine was warmed up?

Well after looking through the '05 service manual it looks like your target idle at normal operating temperature is actually 625 RPM's (+/- 50 RPM's) with no load (A/C off, steering wheel straight ahead, lights off, heater fan off and defogger off, vehicle in park or neutral). So even before you cleaned the throttle body you were idling too high.

Do you remember the actual code that he read off the ECU? I would start with a P and then have four numbers (Example: P0335). I've never heard of a "high idle" code but that doesn't mean there isn't one.

Pwnin O’Brien wrote:Well after looking through the '05 service manual it looks like your target idle at normal operating temperature is actually 625 RPM's (+/- 50 RPM's) with no load (A/C off, steering wheel straight ahead, lights off, heater fan off and defogger off, vehicle in park or neutral). So even before you cleaned the throttle body you were idling too high.

Do you remember the actual code that he read off the ECU? I would start with a P and then have four numbers (Example: P0335). I've never heard of a "high idle" code but that doesn't mean there isn't one.

Light came back on I had no problems with high idle before I cleaned the throttle body...Just came back from getting the code checked and it was P0507 "Idle Control System RPM higher Than Expected"

This is idle at normal op. temp...no A/C...no fan...nothing

Here is a video at start up you can see it jumps to 2500 then comes down to 1500rpm




Modified by wizeguy at 12:24 PM 8/23/2009

Ok, since you are still getting that high idle, then we know that the problem isn't realearning the idle air volume. The code P0507 indicates an error in the ISC system which as you know, was caused by an idle more than 200 RPM's higher than usual. Here are a few more things to check which are likely the cause of the issue...

1. Check your PCV valve and hose to ensure there are no leaks and to ensure that your PCV valve is functioning properly. A new PCV valve is cheap and it will completely rule that out, however I am not sure how difficult it is to replace it on your model, for the models pre-2005 it was extremely difficult.

2. After you start the vehicle, check for any leaks around the intake and mass air flow sensor. Ensure that the filter is seated properly and you have re-assembled the air box and all tubing properly. A good indicator would be a slight hissing noise from around the air box or air intake tubing.

Also, the dangling tube, if the car is running and there is no vacuum present at the end of the tube, then it is likely a venting hose and is supposed to be open to the engine bay. There should be a hose coming from the top of the driver-side (closer to the rear of the engine near the firewall) of the engine which will connect to your air intake tube or air box and it is for crankcase ventilation.

The crankcase ventilation hose I'm talking about is the far right hose in the above picture (11826+C).

I can do some more research into the matter but I will need better reference pictures as I am somewhat unfamiliar with the 2005 engine bay.
Modified by Pwnin O'Brien at 5:06 PM 8/23/2009

I found the oil fill cap barley on (thanks to the Nissan dealer) thought that was the problem but still the same symtoms....The dangling hose in my pic is connected to the trans...must be a vent tube.I triple checked everything I did when I did the cleaning and there are no electrical lines, air lines disconnected. I opened and closed the butterfly manually and it felt fine...I did notice that the butterfly does not close all the way, I can push it closed a couple of cm.

Pwnin O’Brien wrote:Ok, since you are still getting that high idle, then we know that the problem isn't realearning the idle air volume. The code P0507 indicates an error in the ISC system which as you know, was caused by an idle more than 200 RPM's higher than usual. Here are a few more things to check which are likely the cause of the issue...

1. Check your PCV valve and hose to ensure there are no leaks and to ensure that your PCV valve is functioning properly. A new PCV valve is cheap and it will completely rule that out, however I am not sure how difficult it is to replace it on your model, for the models pre-2005 it was extremely difficult.

2. After you start the vehicle, check for any leaks around the intake and mass air flow sensor. Ensure that the filter is seated properly and you have re-assembled the air box and all tubing properly. A good indicator would be a slight hissing noise from around the air box or air intake tubing.

Pwnin O’Brien wrote:Yeah, that's unusually high even after cleaning the throttle body. Do you remember the code number that the guy at the auto parts store read from your ECU when you started having the problem? Also, before you cleaned the throttle body and started having the issue, what was your normal idle after the engine was warmed up?

Can you post the ECU resetting sequence in a new thread as a how to?

Billy

I disconnected the battery for 12 hours and it seemed ok...SES light is back on I don't want to take it to the dealer

Here's what I suggest before taking it to a dealer...

Start by retracing your steps and ensuring everything you removed has been replaced properly. Make sure everything is secure and there are no leaks or missing hoses.

Did you remove the throttle body from the vehicle to clean it? If so, then you should have replaced the throttle body gasket between the throttle body and intake manifold. A bad gasket will generally make a hissing noise when accelerating but it should ALWAYS be replaced when removing the throttle body.

What did you use to clean the throttle body? Make sure you used throttle body cleaner, it contains special oils which will lubricate the throttle body butterfly to ensure proper operation. You also need to make sure that the cleaner was safe for plastics and sensors.

Your throttle body butterfly will not close completely and will remain slightly open when not energized. This is the neutral position of the throttle body butterfly and allows air to pass for idling.

The issue you are having was caused my the cleaning of your throttle body, the issue is most likely something simple and easy to fix. If you take it to a dealer, they will likely charge you $80 to look at it and tell you that the gasket had to be replaced or a clamp was loose.

After you clear the SERVICE ENGINE SOON light, you completed all of the learning procedures, right? After you completed IDLE AIR VOLUME LEARNING, what was the lowest idle RPM's you achieved (on the last step when it tells you to start the car and wait 20 seconds)? It should start out high and then slowly reduce RPM's to an acceptable specification (625 RPM's in your case) in that 20 second period.

Pwnin O’Brien wrote:Here's what I suggest before taking it to a dealer...

Start by retracing your steps and ensuring everything you removed has been replaced properly. Make sure everything is secure and there are no leaks or missing hoses.

Did you remove the throttle body from the vehicle to clean it? If so, then you should have replaced the throttle body gasket between the throttle body and intake manifold. A bad gasket will generally make a hissing noise when accelerating but it should ALWAYS be replaced when removing the throttle body.

What did you use to clean the throttle body? Make sure you used throttle body cleaner, it contains special oils which will lubricate the throttle body butterfly to ensure proper operation. You also need to make sure that the cleaner was safe for plastics and sensors.

Your throttle body butterfly will not close completely and will remain slightly open when not energized. This is the neutral position of the throttle body butterfly and allows air to pass for idling.

The issue you are having was caused my the cleaning of your throttle body, the issue is most likely something simple and easy to fix. If you take it to a dealer, they will likely charge you $80 to look at it and tell you that the gasket had to be replaced or a clamp was loose.

After you clear the SERVICE ENGINE SOON light, you completed all of the learning procedures, right? After you completed IDLE AIR VOLUME LEARNING, what was the lowest idle RPM's you achieved (on the last step when it tells you to start the car and wait 20 seconds)? It should start out high and then slowly reduce RPM's to an acceptable specification (625 RPM's in your case) in that 20 second period.

I will re check everything over again for the 5th time and report tomorrow I did not remove the throttle body...All I did was manually open the butterfly and take a dry, clean rag and wiped the inside with my finger.The idle did start off high and after "revving the motor" a couple of times, the lowest rpm was a tad over 750 rpm.

Check it all out for a hose loose and found nothing...I also lightly sprayed starting fluid (cold motor) around the throttle body, intake box, intake hose and air cleaner box with no "jumping" rpm.
Modified by wizeguy at 12:52 PM 9/20/2009

Don't mean to be a "wizeguy" but maybe it's somewhere else? Perhaps some of the rag you used got loose and traveled inside? It seems like you tried everything but still no joy. In any event, it will be nice to know what the fix is once you find out!

moseng wrote:Don't mean to be a "wizeguy" but maybe it's somewhere else? Perhaps some of the rag you used got loose and traveled inside? It seems like you tried everything but still no joy. In any event, it will be nice to know what the fix is once you find out!

I ran out of options Now it's idles at 1000rpm...I didn't want to take it to the dealer, but I have no choice now.It will cost me $100 to have the dealer tweak the ECM

Well took my truck to the dealer and explained to the service writer that the truck on cold start up jumps to 2500 rpm and slows down from there and the engine idles at 1000 rpm's...he said "thats normal for cold start ups" I just wanted to pull my truck out right then and there!I didn't say anything about me cleaning the throttle body....He called a few hours later and said the throttle body is no good and it will be replaced for free under the emission warranty The dealer did want to sell me a Battery for $150

That's weird, I wonder if you somehow damaged the electronic throttle actuator when you cleaned it. I don't see how, and I've had absolutely no problems cleaning mine. Just out of curiosity, what MAF cleaner did you use? I use the CRC MAF cleaner (pictured below) and I wanna make sure I don't get any adverse effects from cleaning it. At least they're covering it under the emissions warranty, that definitely would have been a pricey part. For $150 you could by an Opitma Yellow top, that's crazy high.



EDIT: Sorry, this was a huge typo on my part. I meant to say throttle body instead of MAF. I think I'm starting to mix up threads. I don't use MAF cleaner on my throttle body and I hope nobody else does.
Modified by Pwnin O'Brien at 11:29 PM 9/21/2009

I didn't use any cleaner....I just wiped it with a clean, cotton cloth.x2 on the Yellow top!...I thought that was ridiculous

Pwnin O’Brien wrote:That's weird, I wonder if you somehow damaged the electronic throttle actuator when you cleaned it. I don't see how, and I've had absolutely no problems cleaning mine. Just out of curiosity, what MAF cleaner did you use? I use the CRC MAF cleaner (pictured below) and I wanna make sure I don't get any adverse effects from cleaning it. At least they're covering it under the emissions warranty, that definitely would have been a pricey part. For $150 you could by an Opitma Yellow top, that's crazy high.

wizeguy wrote:I didn't use any cleaner....I just wiped it with a clean, cotton cloth.x2 on the Yellow top!...I thought that was ridiculous

I'm sorry but I must have been drunk when I wrote my above message. I definitely do not use MAF cleaner on the throttle body. I use the CRC throttle body and air intake cleaner to clean my throttle body.

This stuff...