Guess the problem, and the solution! P0507

[Mudderoy]

https://lh6.googleusercontent.com/-VdQYQ-LtyPI/TlJaBGQ_pUI/AAAAAAAABJ0/WsW2-bcT-oE/2011-08-22%25252008.29.55.jpg

Most recently I had a check engine light and when read I had codes p0700 and p0740.

This went away and came back, and went away. A good couple of weeks now.

This morning another check engine light popped up and I didn't notice any issue until I came to a stop.

As you can see the idle is about 1/2 what it should be.

Before I read the code, what do you think the problem is?

[msmoorenburg]

:) IAC but its a guess

[Mudderoy]

:) IAC but its a guess

I'll be pissed if that brand new IAC has gone bad. :bang:

[msmoorenburg]

I'll be pissed if that brand new IAC has gone bad. :bang:

That's the only thing that controls idle rpm

[Mudderoy]

That's the only thing that controls idle rpm

When I was typing in the post, I thought about my vacuum gauge line. I wanted to put some protection around it. I wonder if I have a vacuum leak. I'll check it before I leave today. I have the original cover for the port on the intake just in case.

[xj4life2]

If your check eng light is on you are in "limp home mode" and this may drop the idle a bit , however yours doesn't seem that low. Vac leak or IAC is my guess

[JENSSEN]

Plugged Cat or 02 sensor

[XJ4IV]

Your jeep is broken... must be a red jeep thing...:hmmmm2:

[Mudderoy]

Okay I have a p0507

This P0507 code is one that's sometimes triggered on vehicles that have electronic throttle control. That is, they don't have a regular throttle cable from the accelerator pedal to the engine. They rely on sensors and electronics to control the throttle. In this case, the P0507 DTC (diagnostic trouble code) is triggered when the PCM (powertrain control module) detects an engine idle speed that is greater than the desired (pre-programmed) RPM. In the case of GM vehicles (and possibly others) if the idle speed is over 200

My idle is low. So low in fact it died twice while I was leaving the parking garage. I used to two feet method to get home.


A P0507 DTC trouble code may be caused by one or more of the following:

A vacuum leak
Leaking air intake after the throttle body
EGR valve leaking vacuum
A faulty positive crankcase ventilation (PCV) valve
Damaged/failed/dirty throttle body
Failed EVAP system
Failed IAC (idle air controller) or faulty IAC circuit

I removed the tube that is running to my vacuum gauge on the a-pillar pod and capped it off on the intake. We'll see if this has any effect tomorrow.

Next I'll put the old "factory" IAC back on it.

[XJ4IV]

might have something to do with the needle on the gauge ...
If the needle looks like this one does... that might be your problem
http://static.speedwaymotors.com/RS/SR/Product/1823432_R.jpg
I THINK if you replace it with one similar to this one you should be ok
http://cn1.kaboodle.com/hi/img/c/0/0/13b/4/AAAADJV4I1YAAAAAATtIWA.jpg?v=1300587693000

[msmoorenburg]

When I was typing in the post, I thought about my vacuum gauge line. I wanted to put some protection around it. I wonder if I have a vacuum leak. I'll check it before I leave today. I have the original cover for the port on the intake just in case.

Vacuum leaks always increase idle rpm :frog:

[Mudderoy]

Well I disconnected the vacuum gauge and capped it off. Everything ran fine this morning. I'll just have to wait and see if this was the solution, although it doesn't make sense that it was the solution.

[Mudderoy]

I was a little concerned that my issue with the TCC code that came up a couple of weeks ago was back. Since I couldn't read the code going home yesterday I tried hitting the brake just enough to disengage the torque convert lock, and it wasn't locking!

I was a little nervous as to what it was going to take to get my Jeep going at 100% (or nearly so) again.

I was surprised to see the P0507 code and even more surprised to see that the torque converter was locking and unlocking correctly on the morning drive to work.

I hope every thing continues to work as well on the drive home.

[Mudderoy]

Well about 1/2 home I received a friendly "Check Engine" light and the idle dropped back down to about 350 rpm.

Having the OBD II hooked up I checked the code while in transit. P0500. Speed sensor?!?!?!

Once I got home I turned off the engine. Restarted and a new code came up, P0505, or IAC failure.

I've replaced the IAC with the factory original. I also hooked up the vacuum gauge since that wasn't the problem.

I am wondering if the IAC is heat sensitive. It was about the time I hit 222 on the coolant that this check engine came on.

I did let the engine cool off before replacing the IAC and when I test started it, the check engine light I had just cleared stayed off and it was idling normally.

I think I got a piece of shit replacement part! Looks like I may be going to the Jeep dealership soon to replace these failing after market sensors.

I was warned, more than once. :(

[Mudderoy]

As the end of my work day approaches I wonder, will my CHECK ENGINE light come on this afternoon?

Will I beat on the dash like a wild man if it does?

Tune in later for the answer to these mind numbing questions!

[msmoorenburg]

so what dose the winner get???? let me guess :stars: a chance to try again :smiley-laughing021::smiley-laughing021:

[Mudderoy]

so what dose the winner get???? let me guess :stars: a chance to try again :smiley-laughing021::smiley-laughing021:

I had no issues yesterday. I guess I didn't want to jinx myself, actually I still don't. A couple of days without the issue and I'll know it was the NEW IAC.

[xj4life2]

oh oh I guessed both vac and IAC I win Iwin !!! So what do I get ??? A free XJ Talk tee shirt ????

[leadfoot]

whys everyone pickin on red? ive got a red camaro :D

[Mudderoy]

whys everyone pickin on red? ive got a red camaro :D

This is why...

http://xjtalk.com/images/special/jeep_photoshoot065.jpg

:rotfl2:

[jeepincori]

thats a pretty jeep

[xj4life2]

thats a pretty jeep


Exactly !!!!!!!