VW Passat No Start - an SDP Case Study (Part 1)

This is part 1 of a 3 part case study where I navigate through this unknown problem live with my class at Rosedale Technical College. We will dissect this VW completely, showing the exact cause of the problem. As with other classroom case studies I will be using any and all possible testing procedures to narrow down the problem area. Speed is not as important as learning these methods. But you guys that have been following along already know that. It's why your here!
part 2 • VW Passat No Start - a...
part 3
• A Smoked ECM AND a Jum...
Symptoms
- no start
- no spark
- no communication
- no fuel injector pulse
00:00 - symptoms/customer complaint
01:55 - No-Start basic checks - 5 volt reference
07:15 - picture - how NOT to back-probe/test circuits
11:15 - checking for spark with an incandescent test light
12:58 - listening to engine cranking - questioning compression
15:10 - Coil-on-plug - identifying wires without a diagram
17:50 - 3 and 4-wire coil-on-plug circuit design
24:20 - COP confirmation circuit
28:35 - comparing wiring harness to wiring diagram
37:35 - illustrating secondary ground
ScannerDanner Tools:
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For more information on this topic, I have written a “field manual” called Engine Performance Diagnostics which is available at www.scannerdanner.com as an eBook or paper book.
Want even more diagnostic training? Whether you are a DIY trying to fix your own car, someone looking to become an auto technician, or a current auto technician that wants to get more into diagnostics, subscribe to ScannerDanner Premium www.scannerdanner.com/join-sc... There is a 14 day free trial.
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.

[@ScannerDanner]

If you don't want to wait for the other 2 parts to be uploaded here to KZbin, SD Premium members can watch this entire class/series right now. In addition we have over 500 other videos you can check out while your there www.scannerdanner.com/scannerdanner-premium-chapters/no-start-case-studies.html Hope to see you there!

[@SMAutoRepairLLC]

Going to have to join wish I could find time to watch all of your videos, so much knowledge you put out and share with us on here and as a small business owner and automotive technician I can’t say how grateful I am to have found you on here.

[@jamiegermaine5395]

You don't know how to spell I don't know how to ask questions😁

[@SMAutoRepairLLC]

@@jamiegermaine5395 Look I’m from Kentucky, cut me some slack lol

[@justinpoole3154]

Scanner Danner! If all young people entering the motor trade here in the UK had this type of training we would have many successful technicians. Your approach to teaching is spot on 👍🏻

[@ScannerDanner]

Thank you Justin!

[@midnightauto9519]

Paul I have been in this industry for 38 years as a diesel tech. Thought Ihave seen everything until i watch your videos. I have to get one of your books seems like there is a lot i can still learn

[@ScannerDanner]

Thank you Edward

[@iannsalise4221]

No. 1 teacher in mechatronics industry.

[@douglash3129]

Hi Paul and class, speaking of 2 grounds, HEI has a bat. neg. and a coil neg. I was putting in a kill switch and I was using the neg. for the kill switch, I hooked everything up, started started the eng. and flipped the switch and the eng. kept on running but I could hear the spark jumping the contacts in the switch,I was using coil neg instead of bat. neg. switched to battery neg. Everything was good! You Sir are a great teacher and you make people want to learn GOOD JOB Paul Danner!

[@isalmankhan1]

First comment before watching the full lecture soo excited to be in the classroom digitally 😍 Thanks for sharing SD❤

[@isalmankhan1]

Superb Thanks for educating us SD👍 Stay Blessed Bro❤

[@Pablo_Automotive]

Nice video Paul. I'm waiting for the next part.

[@gt3tunecl725]

I dont see the video yet, but i am pretty sure that is a great content and info like always. Cheers from Chile

[@harshanakumara192]

Awesome explanation 👍👍👍👍👍

[@mrcoconut9205]

Very informational love it

[@gremling72]

Hi Paul, Audi (VAG) LS2 coils typically have A and B (brown) to Ground, C is signal from ECU and D is +12v VAG coil short lenght coil stub 1&2 brown and is ground 3 is +12V 4 is ECU signal I think one is power ground, the other one is signal ground. Should be quite a difference in thickness of the 2 grounds

[@jackiemay9471]

that Shane is a right smart arse you get one in every class he ll have your job in twenty years good video Paul

[@kenniefernandez]

OUTSTANDING Man God Bless

[@AbbottAutomotive]

Great stuff. 👍🏼

[@romanjaspe4172]

thanks so much paul

[@jacksonlamme]

your a brilliant teacher!

[@ScannerDanner]

Thank you!

[@normangallant9879]

This is a good education.

[@danman9017]

good video thanks

[@imrannazeer1262]

Thank you so much sir

[@francezandamela6065]

I'm watching now I believe I will gain a lot

[@dtnel]

Working on one of these as we speak, immo issue though.

[@akshonclip]

The second ground is used for the secondary winding in the ignition coil because the valve cover it is mounted to is plastic.

[@ScannerDanner]

Yes sir, I catch this later in the video. Thanks!

[@VladGoro25]

Today i finaly fixed NO SPARK no INJECTION problem on 1995 Audi A6 C4 2.6 V6 MPI engine. After checking entire engine control system for a shorted\open power and sensor wires with a scope and swaping an ECU from a donor car it didn't start either. HELLA brand ECU on this can CAN NOT BE DIAGNOSED with scanners i have in my shop (and a lot of people claim the same) so scope is the only way. Than i diged forums, found some waveforms of cam crank and engine speed sensors (eng speed sensor is identical to crank sensor but has different target and thus waveform. So in this car ECU watches 2 crank sensors and one cam sensor). I decided to record waveforms of these sensors at my client's car and they didn't corelate with those found in forums, it seemed that cam was too advanced. After physicaly getting crankshaft in cyl 1 TDC i confirmed that TIMING WAS WRONG on that car and both CAMs were way ahaed of CRANK and somewhat not in time in relation of each other! Then i found the reason - some plastic pieces cracked away from engine cover and got under the timing belt and it jumped. After instaling timing belt with crank and cams in time - engine started after 2 secs of cranking and working again. It cranks 1-1.5 secs every time you start it. That was new experience for me and first time ECU won't give spark cause of TIMING issues + i couldn't use diag tools (HARD MODE ENGAGED :)

[@tomtke7351]

Very, very informative. I'd offer that the confirmation signal might BOTH confirm the control switching AND the inductive reaction of actual firing of secondary. Now that I've learned, I wonder: IF there's no confirmation doesn't ECM disable respective injector? If common confirmation path is open to ECM will ALL injectors be disabled? HOW'S COME, again, did you decide to not get communications back? Isn't there a wealth of data to be gained?

[@albi2k88]

As I know in that VW coils one ground is for primary winding second is for secondary. I connected that type of VW's coils to standalone ECU one time Missfires are detected using cranck speed sensor.

[@ScannerDanner]

I'm focused on showing them what a bad sensor ground circuit looks like. The communication signal may or may not have shown it as an elevated voltage in the network every time the ECM talks. This was more important for the new guys

[@ScannerDanner]

Correct and I corrected myself late in the video. Thanks!

[@markhollins2190]

Nice

[@danielmusat597]

A separate GND wire for the secondary ignition is needed because of EMI compliance. During firing the noise injected in the circuit is huge and the ECU power transistor might fail if the GND would be the same for both inductors (if the wire disconnects from GND, the transistor is in series with the inductors). That's why the GND of the primary is going to the ECU (for closing the loop effectively) and the GND of the secondary is injected in the block of the engine dissipating in a big chunk of metal, reducing electromagnetic emission and closing the loop through the spark plug.

[@brianmason8400]

I'm impressed..... looks like someone has definitely been doing some homework..... thanks for the info.

[@ScannerDanner]

It's not dissipating, the block and that extra ground is the return path for the secondary winding. (I corrected my mistake further into the video and explain this) Thanks!

[@danielmusat597]

@@ScannerDanner Dissipating means a high energy over a small amount of time which has to go somewhere. The electric field is high and it is "channeled" through a small wire. If it goes directly to the spark plug it creates EMI noise around the wire, while, if it goes into a big metal block, it dissipates and the noise goes way down. In other words, the current flowing between the 2 points takes many paths through the block. Electric field (voltage over the block in this case) is not uniform through a medium. As the medium gets thinner, the electric field increases per surface area, and viceversa increasing or decreasing noise.

[@ScannerDanner]

@@danielmusat597 You are complicating something simple in my opinion. If you take that secondary ground away, you will NOT have spark. It is simply a return path. Coil secondary windings are either connected to coil positive or a direct ground (like this one) or another spark plug (waste spark systems). In ALL of those circumstances this is the return path back to the coil windings where we send all those electrons out. That is the main purpose of that additional ground wire. The only difference with the 3-wire coil design and this one, is the secondary winding is attached to coil positive instead of ground. Again, you need a return path!

[@dominikg4334]

cam to crank correlation have to be right in order to have a spark ?. Different flywheel ?.

[@lowerider84]

The car is a quilt with a timing chain and they are known for the timing guide to break. Mr. Value's and Mr. Piston's will meet. Plus the high pressure pump that Paul had his hand on. The fuel pump cam follower can fail and damage the cam. Junkyard motor of the timing jump or spend more for a head plus VW parts.

[@frankgonzalez24]

Just wondering, if the second coil ground is the ground for the secondary coil, could you use an inductive clamp on it to check the sparkplug fire wave form of that sparkplug?

[@ScannerDanner]

It is (I corrected myself later in the video) But no, a current ramp pattern of the secondary will be nothing but noise

[@DependableAutoTruck]

I have a noid light set but always very dim is there a best test light or a bulb that works better. I have one like you like so much haven't tried it. I usually use a stethoscope and listen for injector pulse and spark jump

[@ScannerDanner]

It depends on the type of bulb and control (pulse width) on how bright a noid light will light. Especially if the engine is running. A dim bulb may not be an issue

[@mikesabin8568]

Audi and vw usually have two grounds at cop. Im used to that

[@kevinhedrick6354]

In D.I.N. systems brown is supposed to be I believe terminal 30 or power feed essentially ignition feed. I could jave those wrong, it's been 7 years since I worked for Audi and haven't read D.I.N. diagrams in a long time

[@LynxStarAuto]

All VAG products use two grounds one for the primary, and one for the secondary. The other is a power feed, and the third is a signal wire. This is all I work on, the Euro stuff. Going over 20 years now.

[@troysmith9453]

Never mind tell Shane he's the man cause that's what it thought of 😉

[@briandish1787]

If you don't have Phil's piercing tool a bed of nails will also work!

[@howlinhog]

I'm not sure how much logic is involved with the confirmation circuit; I believe it's just a change of state that the computer is looking for. Next time I see a four wire I'm hooking up the scope and comparing the two. Confirmation should look just like a typical primary side coil pattern and the ECU signal should be a square wave. Going off of your drawing that is.

[@ScannerDanner]

I was wrong about the 4th wire on this design initially but then corrected myself later in the video. Be sure to watch it through for that correction. Thank you!

[@howlinhog]

@@ScannerDanner Yeah, I watched all the way through but decided to leave my comment. Not sure I've ever hooked up my scope to a confirmation circuit. But if we were to imagine that you actually were working on a vehicle with a confirmation circuit and your hand drawn circuit is correct, (I don't know myself), I don't think it would be square, would it? I think it would look like any primary ignition pattern.

[@ScannerDanner]

@@howlinhog I'm so sorry man. I'll upload part two early next week (Tuesday or Wednesday) looks like I only uploaded part 1. As for the IGT signal toyota uses, it is a conditioned signal, it is not a direct tap into coil negative. Hope that makes sense. There is more circuitry involved in the coil. But this extra ground wire is for the secondary. I caught my mistake late in this video. Thanks!

[@zachariajacobussiebert3459]

2009 VW Jetta MK5 1K 2.0 Lt TDI CBD0 Engine, has a P0193 Fuel Pressure Rail Circuit High Input, Sensor has been replaced but problem still there, cars been standing 3 Months. Is there a video out regarding this matter, please help.

[@ScannerDanner]

Absolutely, but not this sensor directly. My chapters 7 (potentiometers) and 8 (pressure sensors) playlists right here on KZbin will help you. You're dealing with a 3 wire pressure sensor, what are your voltage readings plugged in and backprobing with the key on engine off?

[@andreloepfe2539]

Hi Paul, i have heard that VW have a ground for the secondary coil, there is no confirmation to the ecm

[@ScannerDanner]

Yes sir, I caught this mistake further into the video, thanks!

[@manolitolicup5941]

so in that 4 wire design you dont need a capacitor outside the coil? Am I correct?

[@ScannerDanner]

They don't use capacitors on any COP systems, from 2 wire designs to 3 and 4 wire designs. I'm sure they exist within the computer circuitry but nothing external

[@Steve.191]

Super glue seems to work great for punctured wires

[@aymenmohamed1134]

👍🏻👍🏻👍🏻👍🏻🌷

[@charisgrivas4181]

I have a vw golf TSI 1.4 2009.before approximately 2 months ago I was done my test with my oscilloscope and with the multimeter and the test light.i can say that the confirmation signals its not exist by the four pins i found 2 grounds 1 12v and one signal 0 to 5v.

[@ScannerDanner]

I corrected myself later in the video. This second ground is for the secondary winding. Thanks!

[@charisgrivas4181]

Paul you are a great teacher and a mastermind troubleshooter I must say thanks to you because you are the reason for me to have now oscilloscope and be a better technician thanks Paul

[@ScannerDanner]

@@charisgrivas4181 thank you!

[@jacobkmiller]

Man, I wish I was in your class. I've always got questions and it bugs me I can't ask at that moment.

[@ScannerDanner]

Write your questions down, then ask them in a comment after you watch the video. You'll be surprised how many of your questions get answered along the way. But I always make it a point or priority to answer questions from someone who is truly trying to learn. Thank you!

[@jacobkmiller]

@@ScannerDanner ok! I Appreciate you! Also, my dad went to RoseDale back when it was in Homestead. I'm assuming it was 2 years, so he was out in 86-87 or something. Graduated high-school in 84.

[@gregoryfairchild2460]

First thing in my mind is, it ran fine before the timing belt failure. Logically, what could that event have affected. That's my first target areas. Not starting from scratch, crank, no start. No sense checking everything. Unless you're just teaching. What did the failure touch? What did the belt replacer touch?

[@gregoryfairchild2460]

I'm working on a 2003 Silverado right now that I diagnosed with a bad fuel injector on cylinder no#7. The mechanic replaced that injector and the misfire was fixed BUT now it won't shift into Overdrive. Now I'm not going to drop the trans pan and start testing circuits and ttc solenoid etc. I'm going to look at what that mechanic touched first, thoroughly.

[@ScannerDanner]

Watch part 2. I promise it's worth it. Teaching a process was given greatest priority all through this. Not the quickest route.

[@eduardoyepez7358]

Coming from a field tech perspective, we would jump to making sure it has compression before going down the rabbit hole. No sense in spending hundred of dollars worth of diag time if the motor won’t run well. I know this was done for learning purposes but maybe something to clarify next time? Thanks for your videos they keep me entertained

[@ScannerDanner]

We talk about all of this in the next part 😉

[@midnightauto9519]

Paul I get my liquid tape at cumberland truck parts .same place you got your brake cans for your motor home.

[@ScannerDanner]

You remember that! Awesome. So your not far from me then?

[@midnightauto9519]

@@ScannerDanner Uniontown Paul

[@hendrivlieger4642]

Paul getting his feet in euro stuff. Few more months and he will be loving euro 😂

[@ScannerDanner]

I wouldn't go that far 🤣

[@palharley]

Yes, RTV that smells like vinegar uses an acid cure. YES, it is corrosive, but it makes a fantastic adhesive due to the acidic etching properties. Acid and electric bad. Sensor safe gasket RTV okay for electric. Liquid Electric tape always good.

[@ScannerDanner]

Great info, thank you!

[@carlosm7232]

When should we expect part 2

[@ScannerDanner]

Most likely next Saturday. If you're a premium member you don't have to wait, this whole series is there now. Thanks! www.scannerdanner.com/join-scannerdanner-premium.html

[@nickayivor8432]

ACCOMPLISHED Sir ScannerDanner My teacher God bless you for sharing it thank you very much helpful information video Take care and have a great Evening with all your family around you ACCOMPLISHED Sir ScannerDanner From Nick Ayivor from London England UK 🇬🇧

[@troysmith9453]

About those grounds maybe if the main ground for the coil goes it has a second one so the car will still run but will go into some kind of safe mode or it could be for protection of the PCM like you said it's a European our second enemy next to rust 😆

[@ScannerDanner]

I corrected myself later in the video. It is the ground for the secondary winding. Thanks Troy

[@jamiegermaine5395]

When the hell do we get to see the rest of the Volkswagen Diagnosed

[@ScannerDanner]

Why would you ask me like that? I just posted part 1 like two hours ago. I'll get the next two parts up over the next week or so.

[@ivandrago2557]

VW almost always has a two grounds for coils over plugs

[@makdja4957]

Excuse me but you uploaded this video three years ago at this channel.

[@ScannerDanner]

Did I??

[@stuzman52]

@@ScannerDanner He is correct Paul. This video was uploaded three years ago, and here is the link to it kzbin.info/www/bejne/r6LXm52geZWHh9E

[@anjupong4239]

The car is a gdi and if the timing chain broke it's going to bend the valves

[@ScannerDanner]

Just teaching a good class my friend. It's not even about the car. It's recognizing faults. Hope that makes sense why I chose this path. Part 3 will be on Sat and you'll like what we find and the sum up of what we learned

[@anjupong4239]

And a very good content teaching keep up the good work

[@simplemechanics246]

Are you younger on that video? Sure, 2 and 3 we never see but ehhhh...

[@ScannerDanner]

2 is up and 3 will be up this Saturday 10-22-22 and yes, this was from 2016

[@elianbarajas2869]

John thinks he knows more than you, he isn’t going to learn shit. 😂

[@ScannerDanner]

"Sean" was one of the best students I've ever had. I love students like this that engage with me when I'm teaching. But I can understand why you may read this situation differently on the other side of the camera. Thanks!

[@ScannerDanner]

my fault, there is a "John" in this class. John and Shane would be the two we hear from a lot

[@fascistpedant758]

I keep getting more confused as to who uses the fourth wire for what but I've never needed to know anyway. It's just a useless wire, ignore it.

[@ScannerDanner]

🤣 this variation it used the second ground for the secondary winding.

[@tullgutten]

Just about every german/European vehicle needs valves after timing chain/belt has shit itself. And 100% ever VW after 1999

[@tullgutten]

If the valve is good it some times bend or break the rockers. And not completely sure if its for this engine but some vag have press fit lobes on the cam that can spin so it is wrong valve timing from the lobes

[@gsaegerjr]

SO IF I UNDERSTAND YOU LAST COMMENTS RIGHT. IF WHEN THEN DID THE TIMMING BELT. THEY FORGOT A GROUND WIRE OR BROKE A GROUND WIRE. IT WOULD NOT HAVE SPARK. IF THIS ISN'T RIGHT LET ME KNOW.

[@spelunkerd]

Good thought. The other thing that may be close by to the timing belt in some vehicles is the crank position sensor. Leave that connector unhooked and the computer doesn't know when to fire.

[@ScannerDanner]

Part 2 is up and part 3 will be out this Sat. Then if you still have questions I can answer them then okay?

[@howlinhog]

Do the Germans even make a non-interference motor?

[@lowerider84]

Yes some of the old 2.0 vw

[@greatreset3]

I'd refuse a hacked up pile like that! Once you touch it, YOU OWN IT ! 💩💣☠

[@ScannerDanner]

Teaching a class. I really don't care about the car 😉

[@Portuguese-linguica]

When you said no commutation first thing came to mind was ecu issue .

[@ScannerDanner]

But the opportunity I got to have with this class on teaching what a bad sensor ground looks like was awesome, right?

[@Portuguese-linguica]

@@ScannerDanner yes sir . Couldn't have done it any better .

[@cesarsalinas1603]

Danner has washap aolication