P0507 Idle Control System (RPM Too High) - vacuum leak - GM

In this video I will show you how to use Idle Air Control (IAC) position to identify a vacuum leak. It is important to understand that speed density engines (MAP engine with no MAF sensor) can have normal fuel trim numbers with a vacuum leak. This is why understanding how to read and interpret idle air control position on a scan tool it critical.
The type of IAC used on this car is called a stepper motor and it's position is displayed on the scan tool in steps or counts. A "0" count means the IAC valve is fully closed.

Engine Performance Diagnostics chapter 20

Symptoms
- check engine light (P0300, P0171, P0507)
- high idle speed
- poor gas mileage

Fix
- replace power brake booster (leaking vacuum)

Tests shown
- how to interpret IAC motor position on the scan tool
- how to locate a vacuum leak
- why it is important to remember the one way check valve in the power brake booster
- how to locate a leaking power brake booster
- why fuel trim numbers look normal with a vacuum leak

Tools used
- scan tool
- smoke machine

Playlist
- (Chapter 20) Idle Speed Problems and Testing

Related videos
- How to find a vacuum leak with water
- P0506 IAC System RPM below expected (vacuum leak) - Ford
- Causes of lean condition trouble codes P0171, P0174 - GM 5 3L

On ScannerDanner Premium I will bring you right into my classroom at Rosedale Technical College. You will find page for page lectures taken right from my book as well as exclusive classroom type case studies. What is so special about these classroom case studies? I pull live problem vehicles directly into my classroom and we troubleshoot them in real time, using and applying the theory and testing procedures we learn during the classroom lectures. There is no better on-line training of how to troubleshoot automotive electrical and electronics systems anywhere!

Disclaimer:
Due to factors beyond the control of ScannerDanner LLC, it cannot guarantee against unauthorized modifications of this information, or improper use of this information. ScannerDanner LLC assumes no liability for property damage or injury incurred as a result of any of the information contained in this video. ScannerDanner LLC recommends safe practices when working with power tools, automotive lifts, lifting tools, jack stands, electrical equipment, blunt instruments, chemicals, lubricants, or any other tools or equipment seen or implied in this video. Due to factors beyond the control of ScannerDanner LLC, no information contained in this video shall create any express or implied warranty or guarantee of any particular result. Any injury, damage or loss that may result from improper use of these tools, equipment, or the information contained in this video is the sole responsibility of the user and not ScannerDanner LLC.

[jeremyshanks]

A simple approach using scanner data as primary source of troubleshooting, using only the tools and parts removal to verify the failed component, great work. This will certainly cut down on the parts replacing mind set!

[UncleBerniesChannel]

Never mind- found it at your website. Best money ever spent. You're an incredible instructor, man!!

[ScannerDanner]

Thanks for the comment! The smoke machine I am using is around $900. And I agree, what a time saver this tool is!

[teamwindle]

Great video ScannerDanner, this just shows how easy the smoke machine makes it. Dont know how they are priced over in the US but here in the UK I paid about £950 (about $1500 I think) for mine but it one of them tool every time I get it out it never fails to make me happy that I brought it. I know people say you can use propane/brake cleaner but this is safer, on another plus my customers seem to really impressed when I can show the hard evidence why I need to spend hours removing an inlet.

[lam]

Thanks Danny I've been doing this for 12 yrs
And have learn a lot from you thanks master
Danny you are the best in the business.

[ScannerDanner]

I have seen freeze frame data on each code with GMs but not with other manufacturers. And I wouldn't argue about the factory scan tool comment.
Thanks for your input

[kylemcweeny]

Awesome info cant wait to try these new tactics!!

[dohch]

Thank you ScannerDanner.. Your information is GOLD

[careylee]

Great presentation Dan! Yes not everyone has a smoke machine, so I like that little trick you did with hose. I'll keep an eye out on our scanner for the performance of the IAC motor. 

[SuperCarfix]

Another great video from master Danner

Thank you

[gvvq-piml]

Hi Paul I used to do MOT tests over here, and way to test brake servo, was to pump pedal without it running until pedal goes hard, then rest foot on brake pedal, start car and it should sink down..Fred.

[fenixflat]

WOOOO. incredible a want learn mores.... MR.... i from mexico im automotive for me a big honor meet you....SR... thanks

[felmar]

Good video, thanks for sharing your knowledge, and your book is the best. Just gave one to a friend of mine as a birthday gift

[ScannerDanner]

good question. I have found that using freeze frame data to determine the latest occurring code to be misleading. In fact I don't even bother worrying about it. So I guess my answer to your question is I don't know. Maybe someone can add a comment to this that would help us both. I know some cars will give you more than one freeze frame capture and others will not.

[ScannerDanner]

yes but this usually happens on a non MAF engine (speed density system)
when you say performance issues, if it is under heavy loads and wide throttle openings that you feel these issues it is not from a vacuum leak. a vacuum leak effects idle and low speeds only

[SRDFW]

You my friend are a BAD A*S! High Five.

[cincomorales]

Great video I have a 2010 Chevy Aveo LT 1.6 with p0507 idle air control system higher p0315 crankshaft position system variation not learned p0171 bank 1 system to lean p0137 o2 sensor circuit low voltage 1 sensor 2 p0131 02 sensor circuit low voltage bank 1 sensor 1

[mikeconnor]

I am looking for a scanner that can do bidirectional testing, relearn, program ECM's, without spending snap-on dollars. Does one exist? I really like your videos, very very educational. Gonna download your ebook. I have a P0507 right now on an 09 Liberty after installing plugs and cleaning the TB, gonna check the PCV piping for cracks at the elbows. Mike

[ScannerDanner]

Thank you!
It's called a smartboard. Make by smart technologies

[Amopower]

Sorry I meant to use a unit of measure "inches of mercury", not millimeters. It's the chemistry major in me coming out. 650 is actually considered low, for this 4 cylinder at least. 750 is spec from shop manual, with 10deg timing. I also noticed that if I play with the distributor, I can get the idle and vacuum perfect, but the timing is then way off spec. I need to dust off that new Picoscope you caused me to get and put it to good use!