P0507 Idle Control System RPM Higher Than Expected

[firemoth]

Originally Posted by klr050913

About 3 months ago I went in to a local lube shop to get my oil changed on my 2004 Nissan Altima. After they checked my car out, the technician recommended a fuel injection service. Naively trusting him, I gave him the okay. Two days later, my service engine light came on and has remained on. When I took my car back they said it was fine and that the Nissan electrical systems were touchy and the light would turn off in a few drive cycles.

Now, 3 months later, the service engine light is still on and so I took my car to a different shop. This shop told me that a fuel injection service should never be performed on Nissans because the throttle is electronic and manually cleaning it could throw off the entire electrical system. They warned me that the throttle body would most likely need to be replaced at this point.

I want to go back to the original lube shop and have them pay for the throttle replacement since it's due to their actions that the replacement is needed in the first place. I need to have some sort of information or site to prove that fuel injection services should not be performed on Nissans, or some written information that proves that improperly performed fuel injection services can lead to the throttle malfunctioning or breaking.

Can anyone help me? I am by no means a car expert and have really gotten taken advantage of here.

Thank you

Have you tried doing the steps in the above post?

[lighter223]

The Throttle Body most likely does not need to be replaced. Before you shell out for a part plus the labor that you probably dont need do the free and easy thing listed in this very post that you glossed over while typing your problems...

The TB can be cleaned, but a select few really tweak the butterfly (the "valve" that controls the air part of the air/fuel ratio). But if you have a working throttle while in drive but it idles high while in Park or Neutral, then your shit probably ain't broken.

When the MAF or TB is unplugged (with the car on or off and even if you plug it back in before you start the car again) your car WILL throw a code. Resetting it 99% of the time wont work because the ECU itself thinks that the TB is incorrectly set and wants to set it the right way, if you dont then you get an idle around 1500. So you have to relearn the ECU that : this is where the pedal is when I am not accelerating; this is the full travel of the pedal; this is where the butterfly is when I a not accelerating and this is where it is from closed to WOT.

You have to teach every time you unplug it...

Try it before you buy it.

[Chlebek]

If you try to perform idle air volume learn and it won't complete you could have a bad power steering pressure sensor which wont let the ecm to learn the idle thats why it idles around 1500 or jumps up and down, i replaced them before, if you unplug the p/s pressure sensor and it will compleate the Iavl there is your problem.

[KeVQ35]

Originally Posted by Chlebek

If you try to perform idle air volume learn and it won't complete you could have a bad power steering pressure sensor which wont let the ecm to learn the idle thats why it idles around 1500 or jumps up and down, i replaced them before, if you unplug the p/s pressure sensor and it will compleate the Iavl there is your problem.

I actually have a P0550 code coming up which is a bad PS pressure sensor as well as a P0507 (high idle), however my situation doesn't sound as bad as the OP, but I have been struggling for a while now with a high idle issue. Every time I do the reset, it works properly while I am driving the car, but the minute I shut it off, it goes back to idling high; at this point I am done with trying the idle relearn until I replace something else.

I have been reluctant to change my throttle body, as I started to think that was not the reason.

Anyway, how hard was it to replace the PS pressure sensor? I'll PM you for more info, if that is alright with you?

[Chlebek]

P/s sensor on vq motor is on the pressure line from the pump to the rack, take pas. Frt wheel off and you schould be able to see it. P/s sensor on Qr motors is located on the p/s pump. Pm me if you need more help.

[KeVQ35]

Originally Posted by Chlebek

P/s sensor on vq motor is on the pressure line from the pump to the rack, take pas. Frt wheel off and you schould be able to see it. P/s sensor on Qr motors is located on the p/s pump. Pm me if you need more help.

Thanks for the heads up Chlebek. I had to send back the WRONG part and get the proper part from Courtesy Parts. Anyway, you were right on the money the part number is 49763-6n20a (works for the 2002 VQ too).

I got it in last week and had my mechanic look at it this morning while getting an oil change. He called me over to ask me why a harness was dangling. Turns out the plug for the harness on the back of the sensor was busted up and somehow the harness had gotten disconnected. I have no idea how that happened. He also pointed out the P/S pump leak I have--great!!!!!

I'm going to bring it back in on Monday and have them take care of it; too rainy and cold out here for me to be jacking the car up.

[KeVQ35]

-UPDATE-

P/S pressure sensor switch was installed and now the P0550 code is gone. However, when I do the idle relearn, idle works beautifully until car is shut off and restarted, then it goes back to 1000RPM. I have a temporary throttle body my friend gave me to see if that solves my issue. What tools do you recommend to take it off? I was able to fit an allen key in there (hexagon shaped), however there wasn't much leverage to turn it as its screwed on pretty tight. Any suggestions? I am seriously hoping this will solve the problem.

[KeVQ35]

For anyone that suffers from the dreaded IDLE gremlin.

PROBLEM:
You perform the idle learning procedures and it works, BUT once you shut off the car and restart it, it goes back to a higher RPM as if it ignored the learning procedure.

SYMPTOMS:
My idle would always go to 600-650RPM before when I performed the idle learning procedure, however as soon as I restarted the car it would go back to 1000-1100RPM and trigger the SES light.

SOLUTION:
I borrowed a throttle body from my friend (vqaltima) to test it out. By simply replacing the throttle body my idle now sits at 600-650RPM. After that I cleared my SES light and the problem is solved. I need to go buy a throttle body from a junk yard now.

He basically told me that you can LOOK at the throttle body plate and tell its FUBAR. Just look at the plate inside of the chamber, if you can see light on the other side (top and bottom) then it's time for a new one. On my own, you can see through top and bottom. The throttle plate is at an angle, however it should normally sit flush when closed.