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

Thanks for the support Garry

I have to. Knowing the why is key

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.

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

Was it just a regular test lead?

Yes test leads that came with the verus

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. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-XErLeUThZi0.html...

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

Helo

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.

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

Yeah could have been easily missed.

Yes it is.

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.

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

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

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

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! !

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

@@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.

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

Positive Lead Diagnostics gotcha

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 !

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

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

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

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

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

I agree!!

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

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.

+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.

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

Could be a fuse

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

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

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

@@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.

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

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?

@@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?

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

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

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

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

@@PositiveLeadDiagnostics I see, thanks!

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

Check fuel injectors also

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

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

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

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

Positive Lead Diagnostics "

What's the code??

Did u scanned it ?

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.

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

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

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

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

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

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

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

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

Lol no. Regular valve stems no sensors installed

Mines a piece of crap also.