sometimes you just have to watch old videos of yours just to feel special. Even back in 2011 your videos are top notch!

@ScannerDanner

4 жыл бұрын

Haha thanks Cody

Great video. Since we are all here to learn. I will point out that you could also have a bad connection on the one pin that connects to the idle control motor for that one circuit. This bad connection could be the result of a bent over pin on the idle control motor, damaged plug etc. You could unplug the connector do a visual inspection of the connector plug, the idle air control pin and a drag test on the connector plug. Then do a resistance test directly on the motor.

Damnit man, that was impressive as hell. Thanks for that lesson. Kinda took me back to my auto tech days in high school. Damn, now that i think about it, i was in that class the same year that car rolled off of the assembly line.

@ScannerDanner The book is second to none!! I can now confidently throw away all my other manuals which were a waste of money- this book is what I have been looking all these years! Great job on that, it's to the point... I mean, what else can I say??? Money well spent, would recomend it to anyone who is serious about really wanting to fix a problem with confidence!!

Another session of quality instruction. I check on here every day hoping there is another great video. I agree, the flow charts for diagnostic steps from the engineers leaves a lot to be desired. Your way, is by far the best of ANY diagnostic process I have ever seen. The instruction is much appreciated!!!

@jcb1972 For some reason I cannot post a web address in here. Type in "auto computers troubleshooting" in a search box. There is more info. on my book on this web site. You could also go to my channel page and my website is listed under my profile. Thanks for your interest

They do for sure. I believe we have 100% job placement. Of course we have some that end up in other fields too, but that's the way it goes sometimes. Thanks for the comment! Paul

Paul, Another outstanding video !!! Keep up the great work, once again I love your trouble shooting techniques !! Pete

thank you, similar as window motor works goes up and when polarity is inverted goes down, so this step motor is extend and retract, I got the idea. Very helpful your book and the nice thing you stay behind it, I have buy some of your video lecture and I strongly recommend those for the people have not buy them.

A nice visual to support the class room lecture, thanks.

Thanks for the response Paul. I have heard LED lights are safer to use on computer controlled circuits; but as I'm sure you know, many drivers are subjected to much higher loads than most test lights pull. It is the same thing with the ESD wrist bands. Some techs still use them while handling modules, while others laugh when they see one in use. I guess you can never be too careful when dealing with control modules though. Thanks, Matt.

I bet your guys (Rosedale Tech grads) get scooped up quick. Sec.3 is really interesting, tough, fun, and frustrating all at the same time. Good Job, Bud.

This video is worth $1000 + to everyone that watches it that has a nissan or works on them. I had no idea how to test the system and hate throwing parts. I verified that one of my wires has a steady 12v, unplugged the ecm and power goes out. will be changing the IAC chip in the ecm when it comes in the mail. I already pulled the ecm and it doesn't look burned like everyone says but that doesn't mean it's ok. Thank you so much for your work! I made a video of my testing and reference your video and link.

@ScannerDanner

3 жыл бұрын

Post the link! Thank you

@WCGwkf

3 жыл бұрын

@@ScannerDanner kzread.info/dash/bejne/hmt8j6enc8TUl5c.html

@Username64870 Good point about not being able to test some circuits while they are on. Your thought process is good in this situation, just be careful using that analog meter. On some circuits it can be misleading. Thanks for your comments

correct joel, and it takes both coils with the correct polarity to make this design stepper motor extend and retract.

i learned alot.. best instructor ever!!

You are the best paul thank you.

Another excellent video! Thanks so much!

I'm having this issue, I wish this dude was my uncle lol... Brilliant

ThAnk you so much God Bless you guys

@ScannerDanner Thanks for ur reply. Sir I have run in to some circuits where DMM shows 5v correctly but with so tiny current (in some situations we can't test circuits while they are on) therefore we think power is ok but it isn't . that's why i use combine DMM and AMM meter.I often use High impedance scopes to view small voltages and any signals.But any way you are much more experienced fellow than me so i respect your wisdom.Thanks.

@jcb1972 Yes, they do make them. I just don't have one and for the most part all of the output drivers that I am testing are capable of alot more than 200ma. Most output solenoids draw between 300 and 500ma with some higher current ones near 1 amp. The only concern with my light would be a relay coil driver that normally carries around 100ma, but I have tested hundreds of them with this type of light and never hurt one. This is why I never bothered to buy an LED type light. I would like one tho

Good question! Because the coil winding is open in the IAC solenoid. So with the solenoid winding open there is no voltage available in the circuit, ever. So you will not see the voltage drop when it is grounded if there is no voltage available to drop. Hope that makes sense.

no problem Joel. this is a reverse polarity type driver. there are two coils unlike the Nissan that has four coils. on this design when one is powered the other is grounded and vice versa

@TheKeyboardKowboy The ohm test would have been a good follow up and as far as cutting the old motor apart, that is the best part of teaching. I have time to do stuff like that now :) I actually have a video where I repaired a PCM driver in a Nissan using the guts of a Ford PCM. Maybe I'll post it, I haven't decided yet LOL

@vessellsbuzz Agree completely thank you.

@ScannerDanner you sure can. Have a good one.

@Username64870 Good comment, this particular light draws about 200ma of current. It is low enough that I am not concerned about any driver in the PCM with it.

@AutoTechHector We were taught many incorrect things weren't we? Remember the anti-static wrist bands? In my book I have a few pages on this. You must know what your test light current draw is and you must know what the normal amperage is of the circuit you are testing. As long as you test light draws less than 300ma you should be ok to test ANY computer driver with it. Also keep the test light away from airbag circuits. I would agree, no test light should be used on those.

In most cases black lead is connected to a known good ground "earth". There are some situations where the sensor ground is more desirable. Section 5 in my book (I think you have it right?) shows an O2 sensor with a ground bias where you want to connect to sensor ground to see a normal looking O2 pattern. Also Section 21 VRS inputs with a floating ground you may want to use sensor ground instead of battery ground. Another would be if the signal is "noisy", using sensor ground will clean it up

@ScannerDanner Oh you have got to upload that one where you repair an PCM with the guts of a ford PCM. I think we will see this type of work in our shops someday, SMD solder stations are not all that expensive now days and make it easy to make a repair. The only problem will be the identification and location of the failed component on the PCB. I have fixed many of those GM HVAC controllers with a POT from radio shack and when you open it up the board inside is at best very universal.

thank you for this great jop i have question when start engine and masure the feed voltae idle valve is it fiexed voltage or varebil voltage the

Any test light (NON-LED type) is fine to use for checking for spark. An LED test light would have been a better choice for checking these IAC drivers.

Nice, my father has a Vantage pro. God bless bro.

@scientist100

5 жыл бұрын

I got the 600 bucks 2000 series pico with 4 channels, seem to work fine, been using with Automotive version :)

thank you, I understood know.

Hey Danner! Nissan should hire you to make troubleshooting flow charts for their Service manuals.

thanks for the video, I have 2001 doge ram 1500 4 wd 5.9l vin z and checking at the electrical diagram it has 4 wires and each of them comes from the computer and are label a,b,c,d control driver#1,control driver#2,control driver#3,control driver#4, and the snap on vantage shows to test it connect to coil driver and 4 , than connect to 2 and 3 and turn on accessories a/c ,blower motor etc, the problem is the engines start and stall unless I keep my foot in the pedal it stay running ,

@MrRoderickreynolds Thanks Roderick! Are you enjoying the book too?

hey, have similar problem with this, dont know how to follow suit with your test, i have power running the socket, i want to check resistance of the other four wires using multimeter? is that possible?

Regarding the spikes from the selonoids do we have to connect the scope to an attenuator when we test selonoids or only for coils? and if no need, if i connect it , it will affect the readings?

@Username64870 What you are describing is why you shouldn't use an analog meter on low voltage computer circuits. It can "pull-down" the signal voltage that you are trying to test. What you should ALWAYS do to ensure proper DMM readings is make sure the circuit is loaded (current flowing). And also to understand that fast on/off signals will be averaged. I understand what you are saying about an analog meter applying a small load on the circuit but computer circuits shouldn't be tested this way

it fits doesn't it? I know it is an IAC valve but it is still a ground side switched output if you think about it.

Good stuff Mr. Danner this is Hector,another one of your "youtube students" i got a quick question...I see that in a lot of your diagnosis you use a test light, i thought that you weren't supposed to use a 12 volt test light on a computer controlled system because you can potentially damage the PCM. How do you get away with it??

Section 3 bought me here!

Is this how you would test a evap volume control valve also since it has a 6 pin connector also

@MyCooley123 Not without the proper test tool. You certainly do not want to used jumper wires.

hi paul, managed to get a fluke 2 channel scope not very user friendly like pico but will help me understand and try some things out. Question paul should i always connect the black lead to earth or is there ever occasion to connect it to any other part of the circuit dont want to start of making basic mistakes, davie glasgow scotland

how is the circuit design on this,2001 doge ram 1500 4 wd 5.9l vin z, not all of the are ground ?? vantage does not specifies to check for common ground or voltage , thank you Paul

how did you set up the verus screen like that? i also own one but have never seen the screen look that way.

Hi great video thanks. I have ,infinity qx4 v6 3.5L car. when I start the car it's on auto chock after few minutes than it goes to normal rpm but soon after it goes back to 3000rpm and back to 1000 rpm than back to 3000rpm it not stable could it be air control valve iac let me know if possible Thanks

Do you have to use a computer safe test light for this test, or is it okay to use a regular one because you're dealing with 12 volt?

I have a 2000 Nissan in now with this same code, friend said it cut off randomly on him and wont start rite back up all the time. I heard when these iac's go on this car they can fry the computer but this car runs good when it runs but I get no spark when it doesn't....have you ever seen this happen with this code??

Hey Paul is this the same 6 wire stepper type as a 2001 nissan sentra bcz I'm having a problem on one of the ground side switch is lighting when key is on test light to bat pos it lights unhook driver lights off so I sent driver to get fixed put back in same problem any advise or any help would really appreciate it love this car want it to work right bcz I was driving it getting off freeway and it idle so high I almost didn't stop I have to baby's I want them to be safe in car

At 5:55 wouldn't the test light need to be connected to ground to check for an open in the coil?

@MrRoderickreynolds What a comment! Can I post it to my webpage? Either way thank you so much!

I have a 2004 Nissan frontier XE-V6 3.3 L 2WD Desert Runner naturally asperated VG33 3275CC ENGINE , according to everything I've found it says that my idle air control valve harness with the key on it should have battery voltage at the B+ terminal to good engine ground.... when checking for voltage i get nothing my meeter got put on the diode setting and it gave me a 0.4 turns out diode number 5 is part of the iacv on my truck and its F37 under the passenger side panels, so its getting something at the B+terminal except voltage real quick Chilton's manual says that if battery voltage isn't present at b+ terminal with key in the on position that the next step Is to test the circut from the ignition to the IACV that i don't know how to do and I'm not sure what components are part of the circut or where theyre at ...lol any help, advice, websites that actually have the info i need,,,etc would be very much apreciated thank you sir side note i had a crank no start condition prior too all of this , unplugged maf sensor and she fired right up ran ok until i gave it gas.... she d hesitate and want to die i could feather it and keep her going just barely. So i replaced the maf , did the drivers side valve cover wich had a gnarly leak, at the start odd all this i had p0304 cylinder 4 misfire and a knock sensor code, rather then take the lower intake off to get to the knock sensor i reached down and manged to get the harness disconnected gingerly worked it out of the wrap and temporarily relocated the knock sensor to the top of the upper intake get done with all of that , back to crank no start, hooked up my obd2 and cranked it with it on live data it gave me the p0505 idle air control valve code what it said was 'idle air control valve or circut '' so i went out and took the upper back off ... the IACV CAME BACK at 10.50 homes , harness nada except the . 4 diode reading i accidentally took what do i do next ? Over got the wiring schematics but they don't really show much I'm stuck on don't know status... right now but I'll figure it out...I hope I'm open to any of your sage advice thank you for your videos they do help I've got a bit of learning to do yet before I'm a guru but one of these days maybe

Chrysler Iac, so the guy ask me do you think it is the fail part and I said yes so than he told me I will get the valve. I felt confident it was the valve because the techniques you have teach listening for flare up at start up truck did not do that, also the engine stayed running if my foot was on the pedal, we replaced the valve and it fix the problem any way I wanted to see the readings doing for channel but i was not allow I want to learn because I know I will see this problems again thank

EXCELENTE

section 20 in my eBook Joel I have a case study on it

on section 20, from page 16 to 18 I can see the study case but, still I do not understand the wiring diagram what should be 12v what is o v comparing with the follow 6 wire Nissan case study, my question came here because recently I started working for a shop I do smog check and repairs too but, I can see in the shops is trowing parts this doge the one I am asking the owner of the shop told me to ohm the stepper motor, i did and it was in between ranges,I wanted to scope and did not alow me .

It would help if the wiring schematic you used indicated the N.O. and N.C. states of the circuit. It is easy to deduce these states by looking at the traces on your scope. When the key is off (1:15), the yellow and blue traces are pulled to ground. When the key is on (1:30), the green trace is pulled to ground and we can say with certainty that the red trace is also being pulled to ground even though it is not obvious from the display. We know the red trace is being pulled to ground because of the test light used at the end of the video when you cycled the key on and off (8:05). Key-on turned the light on, permitting current to flow to ground. It also would have helped to finish up your testing using battery negative. While it's great that you ruled out a short to ground, it's not readily apparent how doing so necessitates a break in the coil. You kinda glossed over the fact that being able to see voltage on ALL THREE other circuits requires that the problem lies where it does. Simply hooking up to battery ground and testing each of the four T-pins would have rounded things out nicely.

@ScannerDanner

8 жыл бұрын

+Jonathan H I disagree, it's been awhile since I uploaded this and I am going from memory. I proved the low voltage on the one circuit was from an open coil by indirectly testing it. No other tests were needed to be 100% confident of an open winding. Low voltage on that pin could have only been from the following 1. short to ground in the control wire (constant current flow) 2. shorted PCM driver (constant current flow) 3. bad connector at the component itself 4. open winding 5. no power feed to the solenoid I proved 1 and 2 and did a visual on 3, and 5 is a shared power feed that the other circuit was working off of. 4.nothing left but an open coil winding

@jonathanh3632

8 жыл бұрын

+ScannerDanner Totally agree, just trying to leave a few more breadcrumbs for the next guy. It took me a while to figure out the indirectness of your tests.

@armandonika

7 жыл бұрын

+Jonathan H hahahhaah jonathan this happened to me also, but i kept watching the videos because i knew he was right on what he was doing anyway ☺️

I can see activity on the red channel , though its not much there is a slight movement

A shorted driver would read on the battery neg to ground 12v “shorted; The driver in the ECU would cause no communication to the throttle body circuit causing a up and down idle

Paul I'm running into an issue on a 2001 pathfinder as we speak. The control terminals on 3 & 4 were melted a bit. I can see the module trying to control the duty cycle on these coils but it looks like the ground driver isn't coming off ground consistently. In the time span that a single on/off event should occur there are two at times with a lot of long skinny lines going to ground. I suspect this is why I can't get it to go into idle relearn mode. I'm using a basic 2 channel scope BTW. I wish I could post a video of the waveform for you to evaluate.

@ScannerDanner

6 жыл бұрын

IT is common for the 6-wire stepper motors on Nissan to short and take out the drivers in the ECM. I have a case study in my book on this and a lecture or two on ScannerDanner Premium. www.scannerdanner.com/scannerdanner-premium-chapters/chapter-20-idle-speed-controls/359-section-20-idle-speed-controls-part-3.html You need to watch the above lecture. There is a 14 day free trial so you could sign up, then cancel and not pay a dime. But this lecture video covers your exact system. start at 43 minutes in.

@devanjackson509

6 жыл бұрын

Thanks a lot. I'll be happy to check out the premium channel & the lecture mentioned above. It can be hard to convince service managers about these kinds of diagnostic cases because it's often well beyond the scope (no pun intended) of their experience.

Excellent video. You could have measured the resistance of the 4 individual coils of the IAC and that would have given away the open coil

@ScannerDanner

3 жыл бұрын

I rarely use resistance testing during troubleshooting as it is highly inaccurate most of the time. The other reason would be getting to the pins with the components in their normal location (without unbolting them) is usually super difficult to do as well.

@gayanx86

3 жыл бұрын

@@ScannerDanner I agree with you. In my case, my car was stalling in idle. After removing from the throttle body, I measured resistance of each 4 coils and 3 were 25 ohm, the other one was open

You mentioned checking for a grounded control wire with a test light - test light "on" - unplug computer for driver check (agreed). You suggested unplugging IAC as well for this test (to eliminate any back-feed, I would assume). But you would also loose your power feed to the motor doing that, loosing your test light. IAC plugged in would necessary in this situation to maintain feed, yes?

@ScannerDannerPremium

9 жыл бұрын

You would have your test light connected to battery positive as I did in this video. Make sense?

@chrisbartman5125

9 жыл бұрын

ScannerDanner Premium My bad - the little light bulb went on seconds later.

It's me again! What is the resistance and wattage of your test light.Higher wattage test light might over load and damage some PCM outputs and inputs even if you get polarity right believe me, it happened to me once which cost me a PCM LOL.

why do you use the pico when the verus has 4 channels

One question is it possible to bench test gm iac.

i think my EGR is the same as that IAC...and i m thinking, how do i open the egr valve manually(bypass, "be the computer")when checking the flow...any thoughts mr. scandan?

@ScannerDanner

7 жыл бұрын

You cannot manually control a stepper type motor. Especially with it still plugged in like we do with other solenoids and output controls. The danger is too great that you will cook the driver. And the controls themselves are too elaborate to do with jumper wires.

What do they make those lame flowcharts that way? Wouldn't be better to give a proper procedure that really makes sure the part is faulty? Or do they have some other reason to make them in such a way? Cause I've seen this kinda messed up manufacturer flowchart now couple of times already. I just find it weird as to why they are doing that, cause sometimes their procedures are even plain wrong and don't tell you a great deal, if anything after you go through them.

Thanks for the videos. I have learned alot from you. I also have a tool related question. I have a KD test light like the one you use in this video. Is it safe to use it to check for spark? It has a screwdriver handle, and I remember being shocked once using a scewdriver to check for spark. If not I will buy a modern type, but I like my KD. Thanks, Matt

Hi why doesent the scope trace show anything on test, yet the test lamp flickers on/off?

If the control wire was grounded, wouldn't the fuse blow?

P0507 on a 03 Infiniti G 35 4 door, cleaned throttle body, changed valve cover gasket, all sensors are good, no vacuum leak but still at an high idle! Could it be possible that cleaning the throttle body messed things up? Is the air control valve apart of the throttle body itself?

@ScannerDanner

3 жыл бұрын

It needs an idle relearn done if you cleaned the throttle body. It is a very stupid method and is ridiculously easy to do it wrong lol Google it. I don’t remember the steps exactly but it involved stepping on the gas pedal 7 times with the key on and some other weird stuff

BUT i dont get it,the scope is cheking the driver control,so basically you are watching ground to ground but nothing can be seen on the scope, unless like you said YOUare on a 20v scale, wouldnt be possible to see changes of milivolts on the scope on a lower scale?

I have a question, what other things can cause the idle air valve circuit to short other than the idle air valve, electronic engine mounts and tps on 01 infiniti i30

@ScannerDanner

6 жыл бұрын

What do you mean short? How do you know it is shorted? Is there a code for it?

@roymcclain1984

6 жыл бұрын

it has no codes but it idles on start up even when i rev it it idles but when i take of to drive it and come to a stop the idle drops really low and it cuts off. if i try to start it a couple of times it dies then it idles then if i rev it it cuts off. i checked the ecm and the chip that burns isn"t burt. i know that some people say that you should unplug the electronic engine mounts, replace tps and idle speed motor when replaceing ecm. want to know if there is anything else that could burn that chip in ecm.

what is meant by (actual stepper motor value) that appear on the diag device? you find 2 data regards this idle motor 1st is actual stepper motor device 2nd is target stepper motor value. what is the difference between them?

@ScannerDanner

7 ай бұрын

One is the command, the other is a calculated value based on the number of pulses or steps applied from 0. The 0 count can get messed up in the calculation if the valve sticks in any way mechanically

Hello, mine is a 4 pin connector. I unbolted it while still connected to the electric plug and turned the key on, it travelled all the way in and all the way out (about 1cm travels). the vehicle still has a very poor stalling idle when cold but works perfectly fine when warm over 160+ PLEASE HELP

@ScannerDanner

6 жыл бұрын

You haven't given me much to help you with. Maybe check it for a vacuum leak?

@mechanicable5741

6 жыл бұрын

ScannerDanner WHAT? I understood his comment clearly. you can just say if that's the proper operation of the IAC valve or if it's shorted or worn or something. looks like the vehicle operates normal once warm which means the ECU changes the fuel mixture to the other map when it's warm( rich mixture when cold + closed shut IAC no air = stall)

I have tried this test on many a Nissan six(6) wire IAC motors and have not been able to achieve the same results.As a matter of fact nothing happens.All coils have been tested and found to contain desired resistance values.Go figure?

Can a faulty Throttle Body cause RPM issues when releasing the throttle? Say I accelerate then let off the gas at 2k rpm, it immediately drops down to 900 then bounces back up to regular slowing down speed. You also feel the car jerk forward when it happens

@ScannerDanner

4 жыл бұрын

Is it an electronic throttle body or cable driven throttle? It would help to know what you're working on

@BigBoyz33

4 жыл бұрын

@@ScannerDanner it's a 2003 350z. It has no IACV and it's an electronic throttle body

@ScannerDanner

4 жыл бұрын

@@BigBoyz33 I would recommend a throttle body cleaning and idle relearn procedure when you are done before doing anything else. These relearn procedures are very strange on Nissan's and you may or may not be able to do it without an enhanced scan tool

@BigBoyz33

4 жыл бұрын

@@ScannerDanner thank you, I'll try that out.

Sir, my car i20 engine rpm up to 1100 from very low 650 rpm when iscv is disconnected. However, it drops to the same low 650 rpm when reconnected. How to restore normal rpm to 850??

@ScannerDanner

5 жыл бұрын

Post this to my forum. It is free to join and we can definitely help you there. www.scannerdanner.com

@ScannerDanner you sure can.

Ok, thank you

Hi I have seen lot's of techs using only Digital meters to check voltages but some time they mislead us.I checked 5v line with DMM and it showed me 4.8v but Analogue Meter gave me 2v. It terns out that Analogue Meter was correct?because unlike DMM ,AMM meters draws current via its needle coil which add some load but Some High quality High impedance DMM only sensitive to circuit gain.So i use 2 in 1 combine meters. Guys Have u ever been fooled by DMMS?

I thought u couldn’t use an incandescent test light on any computer circuit because of the ma draw being to high

@ScannerDanner

5 жыл бұрын

no, you just need to know the current draw of your light and most are around 200ma

@starventures3355

5 жыл бұрын

Ooo ya true now I remember thank you

Now that's what I call T- pinning the crap out of a connector.

@CHIBA280CRV Mr. Danner is my dads name LOL,

How do we know that we are not gonna fry the computer?

@ScannerDanner

10 жыл бұрын

I have videos on this. In particular my Section 3 lectures on my premium channel. It is free for 14 days. There are also some videos dealing with this issue on this channel under this play list. kzread.info/head/PLE9BA8CBD51B8C48E

Hey ScannerDanner where can I get your book?

@ScannerDannerPremium

9 жыл бұрын

luis ordaz from my website www.scannerdanner.com Thanks!! Paul

@justwuicho

9 жыл бұрын

ok i'll take a look thanks!!

*brought

lol i bet its a bad computer now