2009 Volkswagen Jetta 2.5L- Misfire (Flashing Check Engine Light) w/o using a Scantool

09 vw jetta with a 2.5 liter engine, customer complaint is the veh runs rough and has a flashing check engine light which indicates a severe misfire, in this video I will show you how to identify which cylinder is misfiring using the cyl drop test method and how to identify what is causing the misfire without a scantool. I kept this video low tech (at first) to show you that you do not need the high expensive equipment all the time, how ever I did eventually pull out the scope. I hope you enjoy this video and thanks for watching.

[@baxrok2.]

Holy crap, that was the first time I've ever seen anyone use a meter lead to view a coil signal! Sweet. You showed great examples of old school/new school and low tech/high tech troubleshooting in this one. Well done sir and thanks for sharing this with us!

[@so4real]

Good explanation. Took the extra steps when he knew what it needed but went further in detail in case others had a different underlying issue.

[@rjright7373]

If you have a vacuum leak it will also cause intermittent misfire typically cylinder 1 & cylinder 5, for those guys having similar issues. Be careful of those hoses as they are hard plastic and very brittle, hence the reason I know this information. No issues now pertaining to misfire. Good vid., very simple to do for most anyone. Keep up the good vids., especially the 2.5L as am biased, now owning a 2009 2.5 Wagon

[@train4905]

That was fantastic tom, I loved the way,you used,the test light. Multimeter,and scope,all together. And the waveform explanation was superb.thankyou so much indeed,steve uk

[@worsttintentions]

Big 'ol shocker here, folks. Aftermarket coils failing. Thanks for the vid!

[@duanedonaldson2262]

When the circuit first turns on in the primary and the secondary wave form, it starts to oscillate and then builds up the dwell. You can see that the oscillation is small and does not ring much, this is the visual indicator that there is a problem in the secondary winding, this ringing is the CEMF giving feedback of a good or bad secondary coil winding. In your test of all coils, it shows good ringing except in the bad coil. Great diagnosis.

[@fuckit2707]

You are awesome man!! I liked the testing you did with the multimeter!! I needed that thank you!!

[@guayaco-dm3vu]

Good one..Thanks for keeping it low tech some guys always love the low tech approach first. Seen the test lead tip, its a good one..seen some guys use a penny since is a better conductor.

[@garrybetts3997]

Mate I use to fault find X-Ray Equipment(Retired now) but I Love Cars and still love the chase(Diagnostics) of the fault, so it's a pleasure watching you fault finding. Keep the Good work up and keep sending the videos. Thank you.

[@PositiveLeadDiagnostics]

Thanks for the support Garry

[@ggambrel96]

Great vid man just fixed my daughter 2009 wv beetle!

[@larryhurst8958]

good video, glad you used the lab scope and showed the secondary issue, need to look at both

[@PositiveLeadDiagnostics]

I have to. Knowing the why is key

[@deepbludude4697]

Classic old school troubleshooting well done!

[@Whatintheblueblazes]

Thanks a lot for this! This troubleshooting is exactly what I needed.

[@Whatintheblueblazes]

My car was sputtering and check engine light was flashing. I replaced the spark plugs and still had the problem. This was straightforward and I was able to replace just the one coil that was the problem.

[@DJModsChannel]

DAMN! super useful vid!!! thanks for posting!

[@kyhomegarage3430]

I really like test lead tip. Didn't know you can do that. Thanks for sharing.

[@PositiveLeadDiagnostics]

thanks for watching, I finally could use that test, usually you see a shorted coil looking at amperage

[@jdean399]

Was it just a regular test lead?

[@PositiveLeadDiagnostics]

Yes test leads that came with the verus

[@pontesmocho3140]

Positive Lead Diagnostics. Hi mate congratulations on your job.. My sharan 1.9 tdi PD 2005 automatic start fine but after 40 degrees start roughly idle.. Did you have any idea about it? This is a my engine. kzbin.info/www/bejne/jnbVfZiLic2Nn5I...

[@train4905]

As always,superb sir.steve from the uk.

[@MechanicTechnicianRepair]

excelente diagnostic amigo.

[@idris7910]

Thank you bro. I was able to fix the problem thru your video.

[@jaredjones8699]

Super helpful video, Thank you

[@moisesrico4643]

Thanks! This was really helpful!!

[@jasonmorris2813]

Someone who knows exactly what he's doing. Thanks for your time :⁠-⁠$

[@josephtucci3666]

Great vid. my friend. Glad you broke out the scope but that Is just me! Best of luck to ya.

[@Pablo_Automotive]

Really nice Tom is very informative and good explanation, my favorite videos is when have trouble the ignition. Regards from Spain =)

[@PositiveLeadDiagnostics]

Spain!! That's awesome. Thank you for the support.

[@chayvirak2163]

Helo

[@rickdavid1795]

Excellent video Thanks

[@joseblazquez2178]

Appreciate the video, I would not touch a coil on a running engine, as they have very high voltage though

[@jptrustno1]

Dang, thats good u know how to use the scop on that verus. I have a modis edge and dont know how to use the scope at all. I wish i did on this 09 beetle im working, itd be great.

[@Mako-sz4qr]

Great video man... thx 👍🏼

[@2signalman]

My 2014 TDI feels like it sometimes starving for fuel glow plug light comes on and flashes, losing power but still going forward Fila jilting in the car like it's starving for fuel engine light comes on. Put it on the scope they can't find anything. Turn it off and then turn it back on and it disappears. Any suggestions?

[@RealMERealME-zm1kk]

Wow I have been try to find out what was wrong with my car I have a 2008 2.5 Jetta and it sound the same why thanks good video

[@thecommenter7201]

Excellent diagnosis. What if I have intermittent P0302 when the power supply is lower than 13.8V? Other cylinders do not seem to be suffering from low voltage. Should I dig into 2nd cylinder? The engine has slight vibration if that matters (2.5L CBTA).

[@robj7481]

Thanks, very informative. Only one issue with your video. Speaking as an electronics engineer, your voltage check of the ECM output at the plugs has one problem. When you check for a valid ground at the connector, you should move your positive DVM lead to a known +12V connection first, then check for good ground on the ground wires. The absence of a voltage at the ground wire (you show .001) can also mean no continuity at all. You could also set to ohms and read continuity from connector ground to known ground source, but this is the less efficient method of confirming ground as even a slight resistance in the wire can cause a volt drop.

[@PositiveLeadDiagnostics]

I understand what you mean by switching my lead to actually show a voltage. Rather than zero meaning good ground or no ground. But when doing the ground to ground voltage drop test if there is an open in the harness that voltage will fluctuate with some noise. If the ground is good it will read steady. But I understand your point.

[@PositiveLeadDiagnostics]

Your talking about the transistor ground check at the coil right?

[@b00m83]

Thank you Sir!

[@happyhearthappylife]

Dude.. great job.. I fix problem .. so quick and easy once I swap coils. I have tested the resistance b4 but didn't show any problem. PS. I wonder if mechanics go into such details aswell and why. If I just replace bad coil is that covering up the reason why it may go bad again and again????

[@EXOVCDS]

Nice!

[@mbarry9737]

That's a good one. If you would have started looking for a bad coil with an amp probe, could have missed that from the waveform and end up having to back track. I could see easily bypassing that coil.

[@PositiveLeadDiagnostics]

Yeah could have been easily missed.

[@ismaelacosta375]

I have a 13 Jetta GLI. Had some issues with misfires on cylinders 1 and 3. I changed my spark plugs, ignition coils, and did the carbon cleaning of injectors and valves. Getting a P300 code now. Any idea what it could be?

[@zvonimirbobicex-4962]

i think it`s high resistance in (or almost open) secondary winding..the turn off oscillation is more pronounced on the bad coil

[@bluntslayer]

@ positive lead diagnotiscs I had that same problem with C1, I swapped it to a coil i know it was good problem went away. I turn it back on a few minutes late and i hade a misifre now from c1 and 2. Would this be wire related? I went back to check the spark gap, it was fine. put it all back together and back working again.

[@pedcas5715]

I have the same problem on 2009 rabbit 2.5L I already replaces plugs and coil and still flush check engine light coming on I check the way you do with the meter and notices that I don"t get the battery voltage I got 11.7 if that be a problem?

[@nelsonhuard1]

L got the same problem and I changed all coils 5 and spark plug. That is fixing the problem

[@haligraham7450]

Hi! Ik this vid is old but my jetta sounds similar with that loud fluttering noise do you know what’s causing that?

[@kawatan1228]

Nice thank you

[@stmbaah]

Big thanks!

[@pitergutierrez9396]

Nice video you know if the jetta end beatle 2.5 it's same motor thanks

[@msgtblbj]

When you did the coil test in the very beginning, was the drop in RPM from the 2nd coil due to a good coil no longer receiving electricity? And the first coil was a faulty coil because it didn't respond to no longer receiving electric? I am a huge amateur mech looking to buy this year/make/model. Thanks for the video.

[@Crabby_Abbi]

The drop in rpm shows the engine loosing another cylinder and therefor a good coil/spark plug... the reason cylinder 1 never made the engine drop revs was it was already dead.

[@cinthyarodriguez5949]

I have a 2009 2.5 jetta I recently changed the spark plugs , but my car keeps going on limp mode again just started today with no code . Has anybody had this issue ? So I should go ahead and change coils ?

[@stringsnare]

Would misfire cause high idle at stop?

[@chekelley6861]

I think you called the dwell time the firing line but great video as usual!

[@PositiveLeadDiagnostics]

Your right I did lol. I couldn't think of the term. Thanks!

[@PositiveLeadDiagnostics]

There is dwell time building up the magnetic field then the turn off is the firing line and then you have the spark line. Couldn't think of that term. Thanks again

[@richardmcwhirter9396]

great video thanks again for showing us what we should see when testing,is the probe just the standard one that comes with the verus?

[@PositiveLeadDiagnostics]

Yes it is.

[@nando4755]

I m a little comfused here ! 4 wires on coil harness. 1 is feed wire 12v 2 and 4 are grounds and 3 is refrence voltage from pcm !! Now. I had a misfire on a car just like urs !! I pulled each coil !! They were pluged in and there was a strong spark on all of them !! I pull out one by one to see the spak !! Where i m comfused is when i checked all the wires i had 12v on pin 1 !! Pin 2 3 and 4 they were ground so i m thinking 3 pin only becomes 4.3v once in a while or what !! how does dat work !! The other thing is i try connecting a test light to body ground i could see the coil spark but when i would put the test light on the coil like u did the test light wad not arking !! It would do it if i was to put it on battery posite and then put it inside coil !! If u can explain dis i would apreciated thx !! U may contact me 1 408 648 8879 thx

[@andyhuang7526]

I usually replace all the coils and spark plugs !

[@orlandogarza9289]

My 2006 Jetta , 180,000 km, manual trans after SMF clutch replacement started running horrible and misfires and makes a rattling noice on top of engine at 1500 - 2000 revs. Before the clutch replacement it was Runing alright. so far I had replaced spark plugs , coils, MAF, MAP, crankshaft position sensor , cleaned the injectors, installed the old DMF clutch back , troddle body cleaning, replaced the whole harness , i replaced the vacum about 1 year ago, I can't find any vacuum leaks , cylinder compression its 150 in all cylinders, gas pression it's allring according to my mechanic. The problem still there and it seams it's getting worse . The vag scan trows codes p0300 , p0305 and some times p0305 . My mechanic tells me maybe the MCU has corrupted or something , could this be right ? I don't know what else to do . I have already spent tons of money could it be the ckp sensor?. Any help would be appreciated

[@epoyanej8285]

Sir.. your vid. Is so helpful... But i wonder if you can fix the engine that shakes hard by yourself... i have a jetta 08 2.5 And the engine makes loud clacking soud and shakes hard... any idea what could it be? Thank you...

[@PositiveLeadDiagnostics]

I think on the older 2.5 engines the upper chain would stretch causing misfires and an intake system leaking fault

[@philh9238]

nice

[@juergenscholl2843]

I venture to suppose the secondary windings were shorted ...... An open would have driven the firing line way high and the bad coil showed less kv demand than the good ones. There are also missing the turn off oscilations on the bad coil showing that he energy was just almost completely drained off..... If you had the chance to view the spark kv point/spark line with a very short time base it might show more details. Thank you for your time and dedication!

[@PositiveLeadDiagnostics]

There was no spark line at all. I don't think it was shorted Other wise the amperage waveform would have showed it. Analyzing ignition can be difficult. Thanks for supporting !

[@juergenscholl2843]

Positive Lead Diagnostics the amperage waveform shows u the condition of the primary windings..... a shorted (or missing) SECONDARY winding will only be spotted by less - or missing- "ringing “ of the turn on/turn off oscillations, just like in a single coil device like any solenoid, eg fuel injector. Hope this makes sense.... thanks again

[@PositiveLeadDiagnostics]

A shorted secondary will affect what the primary amperage waveform looks like. Look at the misfire video I did on the jeep. Shorted secondary windings will show on the primary waveform

[@PositiveLeadDiagnostics]

The next one I get that is similar to this one. I will dig a little deeper maybe smaller time base for more detail like you said

[@mevsme6416]

good stuff. why dig deeper after discovering the coil was bad tho?

[@PositiveLeadDiagnostics]

just my preference, I like to be able to prove and show why

[@mevsme6416]

Positive Lead Diagnostics gotcha

[@semifredigmailcom]

what is this howling sound from the engine?

[@haywardsautomotive6156]

Way to cover all the bases from simple quick checks & swapping coils to lab scope waveforms. Aftermarket coils suck and all I use is either Wells or OEM.

[@PositiveLeadDiagnostics]

Have to do it for the guys with and without the equipment

[@haywardsautomotive6156]

I agree!!

[@wysetech2000]

After market coils can't be much worse than OEM.

[@haywardsautomotive6156]

AM coils suck b/c you never know what you'll get and I don't like comebacks so I use OEM or Wells. Some of the Duralast coils are actually Wells coils and you just have to look at the Duralast descriptions and it will say if it's a Wells coil. That's just my preference and what I put in my customers cars so they don't have any issues. After trying differnet AM products for over 40 yrs I know which ones have failed me and the ones I trust...I give them all a chance but seems to be a crap shoot with most.

[@wysetech2000]

+Hayward's Automotive You're 100% right in your thinking and i believe the same but my point was that VW can't make a coil that lasts either.

[@getsudatensho]

I got 09 jetta 2.0 cranks but there is no power getting to any of the coils any ideas what could it be?

[@PositiveLeadDiagnostics]

Could be a fuse

[@dezblyan5125]

Good stuff keep em coming why u only work on those kind of cars BMW and stuff?

[@PositiveLeadDiagnostics]

thanks, I work on whatever comes my way, but a lot more vw because I work at a dealer

[@brittany6229]

Thanks so much for putting together all these videos! There isn't a ton of diy out there for vw's.... man what I wouldn't give to have a decent mechanic like you in my area... the locals just wanna throw parts at it. Half the time I have a better idea what's going on with my 2 veedubs then they do! PLEASE keep em coming! !

[@cosmicmirror1320]

Cause German cars are the best.. Domestic cars are just that, mass produced with no real value

[@russelhalili3024]

@@PositiveLeadDiagnostics can you please put some input on my father inlaw jetta. Light engine check and its stalling on long drive but never in short drives. Please help.

[@theantillano6701]

Just changed the coils and spark plugs a year ago, and getting problems again this isn’t normal is it?

[@PositiveLeadDiagnostics]

Depends on the quality of the parts you used. Aftermarket?

[@johnbreen5988]

I have a 2010 Wolfsburg edition six speed 2 L turbo, my check engine light came on this morning out of nowhere. Yesterday I noticed a little bit of shaking while the car was idling more than usual and then this morning my check engine light was on.Went to AutoZone they informed me it was a misfiring cylinder. Does anybody know about an estimate on how much it would be to fix the cylinder? Appreciate it and thanks for the vid man.

[@davidloera847]

john breen I got a gli turbo n same happened out of no where on me today lol this morning

[@pczapp827]

I have ask--2008 was the year all vehicles had to have TPMS ? I asked because I saw the light on the dash Please don't tell me another shop swapped out the TPMS when they are subject to fines,if anyone ever enforces that,who knows

[@seanwickham8905]

New plugs and coils fixed the issue for a month or so, but this morning it was misfiring this morning on a cold day. The car has not been driven a whole lot over the past month and a half, so could that have something to do with it?

[@pskauto6798]

Not just good , good enough

[@ylmazototamir9926]

👍

[@armandonika]

Why it has 2 ground one of them its the feedback signal right? Or maybe not because with the feedback if you unplugg it will turn off the car. Nice vid though Tommy!

[@PositiveLeadDiagnostics]

One is the main ground for the coil. I think the other is for the transistor that is built into the coil. There is no feedback circuit on this one

[@GigiBeleaDK]

If you wanted to keep it really low old school you should have just swapped the coils from the moment you realized which one is bad :)

[@PositiveLeadDiagnostics]

yeah but I have to do it for the guys with and without the big tools, thanks for watching

[@edwardthayer9386]

Hello, I'm having a issue where I'm getting a p0353 and p0303. I have all new coils and plugs. Number 3 is not contributing. When I check the plug harness connector the readings are all the same on all the plugs except number 3 3rd pin that goes to the ECU. The 4 other 3rd pins are reading 11. But number 3 3rd pin is reading 6. Would that mean that the harness connector is bad? Or is is something inside the ecu? Thank you so much for any time and help. I greatly appreciate it.

[@PositiveLeadDiagnostics]

When you are checking voltage is the vehicle running? That connector should have a power and ground for the coil. A ground for the transistor that is inside the coil and a small square wave signal to fire the coil

[@edwardthayer9386]

@@PositiveLeadDiagnostics no I just have the key on. The 4 other coli harness plugs have around 11.97 to the number 3 pin. The number 3 pin on coil plug cylinder 3 is only 6.27. When I changed the plugs around you can see the others have been firing but cylinder 3 plug smells like raw fuel. I did the pull the harness plug when running and all cylinders stumble when unhooked from coil, number 3 acts the same, no change. They are all new coils, I've swapped them around but get the same thing. I even replaced the harness plug today, nothing, same thing. I'm a decent mechanic but I've always hide from electrical stuff. I wish I didn't but I'm trying to learn the basics now. I'm sure that there is a easy way to test this, you'd probably have it figured out in 5 minutes. But I'm literally driving myself crazy. Any help would be greatly appreciated. I do have a decent multimeter. Just not sure how to really use it outside of the simple things.

[@edwardthayer9386]

@@PositiveLeadDiagnostics Codes are a p0353, p0300, p0302, p0303. Crazy part is cylinder number 2 is firing fine.

[@PositiveLeadDiagnostics]

Don’t worry about the cyl 2 code. Its probably flagging that code because of the severe misfire from cylinder 3. What is on pin3 (small wire) when it’s running?

[@edwardthayer9386]

@@PositiveLeadDiagnostics hey man I greatly appreciate you helping me out. I just put a shit load of money into this car, tires, wheel bearings and believe it or not it's a 2011 with drum brakes. I fully rebuilt them. At first I thought it was a nightmare because I didn't understand the teardrop auto adjustment deal. Once I figured that out they were super easy. Anyway I had to go out in the freezing rain (I'm in Delaware) to check but its totally worth it because I really appreciate your time! I went and bought some T-Pins and did the reading on wire number 3 and it's worse when running, it was bouncing between 2.7 and 3.1 when all the others number 3 wires of the other coil harness plugs were always close to 12. I also have a new code of p2307 and p0458. Is the p0458 because I have the air filter assembly removed?

[@noalwright5569]

How to check coil packs

[@rootsdat]

Mk5 gti p0300 p0301 p0302 p0303 p0304 p0455 p0171 p0507 flashing check engine engine , sometimes solid. Loud engine, vibration. Loud exhaust. Any idea what this might be? Hope my engine is not blown :( I checked the oil and its black and smells a little like gasoline . Any help would be greatly appriciated!!

[@robertomorales3009]

Hii what If I Have Misfires On All cylinders?

[@LocalKyRapGame]

Then u have an issue from what sends the fire signal...which most likley ecm

[@JuanAlvarado-fv6xn]

Check fuel injectors also

[@Simon-dm8zv]

Wouldn't the spark voltage be way too high for the test light?

[@PositiveLeadDiagnostics]

Nope. Just giving it a path to ground. It does not hurt the test light

[@Simon-dm8zv]

@@PositiveLeadDiagnostics I see, thanks!

[@ThadmanKane]

And then after swapping coils the misfire still exists on #1. Raw gas on plug during idle, zero misfires above 2k rpm. Voltage and ground checks passed.

[@PositiveLeadDiagnostics]

You could swap the plug too. After that it would be compression or fuel. I think the older 2.5s had head gasket problems on cylinder 1

[@ThadmanKane]

@@PositiveLeadDiagnostics new plugs and coils were tried with no luck, turned out to be a head gasket in the end. Thanks!

[@Activsoul]

My 2009 Jetta sportwagen (2.5L non TDI) diagnosed as a misfire, not a flashing check engine light, just solid yellow. Replaced all five spark plugs and coils, and still have a check engine light on. What would the next step be? take it to a professional at this point?

[@PositiveLeadDiagnostics]

Did you clear it and the light came back on? What's fault is stored and is it misfiring?

[@Activsoul]

Positive Lead Diagnostics have to take it in to clear it, unless there's a way to do it without special equipment

[@PositiveLeadDiagnostics]

Sometimes disconnecting the battery will do it. Does it misfire?

[@seanwickham8905]

Doesn't seem to misfire anymore, but disconnecting the battery didn't reset it.

[@JeezeOK]

Positive Lead Diagnostics "

[@travisshipp7888]

1cyl Jetta

[@andreamel4688]

Hello. Can you please help me with an issue on vw tiguan 2009, error cylinder 3 missfire. I already changed the glowparks, injectors and others and still the check engine lights comes on. Thanks a lot. I have to mention that the car works perfectly, it's just the check engine that comes on

[@bubblecap9872]

What's the code??

[@bubblecap9872]

Did u scanned it ?

[@sara78130]

thankssssssssssssssssssssssssssssssssssss

[@ThadmanKane]

I'm guessing PCM then, if all coils and harness check out. Intermittent dead misfire on #5, then zero misfires for 20 minutes then a dead misfire #5 while running a misfire monitor on all 5 cylinders. Freaky.

[@fullblownredneck9623]

A few weeks later that car will be back, this time for a catalytic convertor

[@PositiveLeadDiagnostics]

I have to say vw makes some good cats. This vehicle never came back. Even after seeing injectors stuck wide open. Never had to replace a cat because of it.

[@chriscanty8214]

why would you not hook to battery ground

[@pczapp827]

My question as well -- what is the problem with using the battery ground terminal vs: the body ?

[@slickrick343]

pc zapp nah its a safety thing while doing that particular test, there is a danger if you are say not clipped to the negative battery lead correctly then you could get a stray spark right above a battery, now when the battery is been charged the gases it releases are explosive, so that's literally it, just a safety thing

[@PositiveLeadDiagnostics]

That's exactly it. Safety. Potential for the battery to explode if it's gassing and your introducing 20000 volts straight to it

[@mypicture7151]

My friend was just charge$500.00 to fix misfire, problem possible was coil pack?, They ripped he off, Yes.

[@drivewasher]

I would have at least checked the plugs even renewed them with a new pencil coil

[@PositiveLeadDiagnostics]

Plugs were replaced a month before and the customer did not want to replace them again. Plus we knew it was a coil problem after swapping and re-doing our cyl drop test

[@drivewasher]

See what you mean. It's always in my mind what caused the failure.

[@PositiveLeadDiagnostics]

Absolutely. I should have mentioned that. In this case the coil was aftermarket junk.

[@markflierl1624]

2:00 That's a 12 volt test light, it isn't supposed to be used for high voltage.

[@PositiveLeadDiagnostics]

My test light works great. I’ve done this hundreds of times. The test light is used as a safety to pull the spark straight to ground. That is it’s only use in that test. A path to ground rather than your hand

[@markflierl1624]

@@PositiveLeadDiagnostics Doesn't the high voltage burn out the bulb?

[@Jettrap505]

a scan tool is faster with this carr

[@crzyofficial7658]

Fuck man I regret buying my vw, 60k miles on it and this shit happening. Had a scion tc, lasted me until 230k

[@coolcarreviews0129]

Mines a piece of crap also.

[@pczapp827]

Customer --- doesn't care about the TPMS issue either ?

[@PositiveLeadDiagnostics]

Lol no. Regular valve stems no sensors installed