VZ Commodore Running Rough Intermittently - P0201 Engine Light On

Today we get a VZ in that runs rough intermittently. It has had a whole heap of work done to it already that has not fixed the problem. Let's get to the bottom of it. Subscribe and hit the notification bell if you like this video!

[@jbilly2946]

Great case study Rob. Cheers for the effort of sharing it

[@romanosautomotive]

Legend Jean, thank you!

[@scottpickford2271]

Thanks for the detailed explanation and demonstrating the injector resistance returning to normal range when warm. I have exactly same code and symptoms in my VZ.

[@romanosautomotive]

Awesome Scott, thanks. Did you get yours fixed?

[@leonwardle9409]

Great work, great diagnosis! cheapest and simple first - especially with an intermittent.

[@romanosautomotive]

Thanks Leon, much appreciated!

[@isalmankhan1]

Thanks for sharing Bro, Great work👍 Loved the LOADpro Test Leads, I use them all the time, great tool to have in our arsenal😉 Great content, Stay Safe👍

[@romanosautomotive]

Thanks again Salman and I love the Loadpro leads!!

[@decimalauthor]

Now I know what to check for my car (which is the same) it's also running like crap randomly. Thanks heaps! Great video

[@romanosautomotive]

No problem, thank you for watching!

[@bosivain]

Hope the customer didn’t pay for that previous repair! Love your content by the way professional and informative as always.

[@romanosautomotive]

He paid every penny unfortunately! Thank you for the support Bosivain!!

[@kirkabrahamson1148]

Wow. Thats gonna be one happy/unhappy customer. Happy that you have sorted his issue but unhappy he has been ripped by someone who had no idea. Great job Rob

[@romanosautomotive]

Thanks Kirk and crazy hey! He certainly was not impressed but happy that it's finally solved. Thanks for the support like always!

[@Jimmy.meyer.76]

Nice work! Good to find the actual fault rather than loading the parts cannon. Customer should be very happy.

[@romanosautomotive]

Thankyou and yes he definitely seems happy!

[@georgepatuaka391]

Serious note Awesomeness absolutely cheers 🍻 bud

[@autosmartmechanicalecutuni479]

Nice work mate. 👊🏼

[@romanosautomotive]

Legend, thanks Luke!

[@donaldisrael7147]

Nice diagnosis.I'm retired now but a lot of electrical problems are created-glad to see a component failure.

[@romanosautomotive]

Thanks Donald! Always that sense of satisfaction when you can prove the component is failing

[@rEdHoUsE_1969]

Kudos Rob 👍 Clearly the previous shop just had a 'scatter gun' approach to diagnostics. Well over a grand (I'd imagine for parts & labour) with no improvement. Your now the official 'VZ Whisperer' ... ✌

[@romanosautomotive]

Thanks Darren, although it's more yelling and screaming at the car instead of whispering most of the time :)

[@user-jz1ht8ry2w]

It depends who's paying?

[@shaunblakemore7150]

Great job 😃

[@romanosautomotive]

Thanks Shaun, much appreciated!

[@Username64870]

Good Work..!

[@romanosautomotive]

Thank you again Dean!

[@fucknbullshit]

Very thorough. I thought it was fantastic when you’re tried the heat gun. something I would’ve never thought of and it’s probably what’s is going wrong with my car. It definitely stops when the car is warm

[@romanosautomotive]

Cheers. Have you got a similar problem and a similar code?

[@fucknbullshit]

I mustn’t have had a misfire yet because there are no codes coming up on it but there’s just this uneasy idling and it does change in intensity. I reckon it tends to be less when the car is warm. I do have the factory single system exhaust but it goes into a stainless “cat back”. I know this isn’t very happy or sounds it, but I’m not sure if that’s what could be doing it. I haven’t had the car that long.

[@Jo-hannson]

bought also an autel scanner, pretty good for the price tag :) good stuff man

[@romanosautomotive]

Great scanner Johann! Thanks for watching!

[@DJ-tn7vj]

Hi Rom. I like your thought process. Going to try it

[@romanosautomotive]

Thanks Daniel, let us know how you go! Send me a message on Facebook!

[@DJ-tn7vj]

@@romanosautomotive will do. Thanks

[@jeremystone6613]

Thanks Rob.

[@romanosautomotive]

Thanks for watching again Jeremy!

[@georgepatuaka391]

Awesome

[@vanhaile6959]

Character In the video It's great, I like it a lot $$

[@romanosautomotive]

Van Hai Le, thank you!

[@vin6455]

AWESOME

[@romanosautomotive]

Thanks Vin

[@mechanicmatt871]

With the injector not being accessable it did make sense to have one ready while you were there, the residence test showed it to be way out of range. Good seeing how a warm engine could have fooled someone.

[@romanosautomotive]

Thanks Matt, you nailed it!

[@geraldwilliams3550]

I had one similar this week. 2008 Dodge Avenger , P0204 . It ran perfectly and had a perfect pattern on the scope. To duplicate the complaint I drove it 8 miles and then hot soaked it for ten minutes . At start up it was missing , reattach the scope and found nothing on the control side and 12 volts on the ground side . Measured the resistance it was completely open. Replaced it and when the old one cooled it had 15 ohms of resistance. I always enjoy your videos thank you .

[@romanosautomotive]

Awesome Gerald. Persistance is a great quality!

[@RussellBooth1977]

It sounds like the other workshop didn't have any scan tools to diagnose the fault with. I had a similar issue in my first VL Commodore over 20 years ago where the primary ignition coil resistance was 11 Ohms (bad) & it stalled after the engine warmed up when it was idling. My point is that the ignition coils primary resistance should've been 0.9 ohms & I fitted a spare Nissan RB30E ignition coil which fixed the problem. I was an apprentice electrical fitter/mechanic back then!

[@romanosautomotive]

Awesome Russell. Are you still in the trade or had enough?

[@grabovg]

Amazing job my friend!!! Way to prove the theory. Did you happen to scope it when it was cold at all?

[@romanosautomotive]

Thanks Gera!! No we didn't, we didn't find out from the customer that it only happened when cold until the next morning once we already had it apart. Such a shame but that shows the importance of us getting all of the information from the customer before the diagnosis.

[@AldiShuli]

Nice job Rob. I see you have added also autel in your arsenal. Give us some reviews if possible please. And what is the webpage you used in the end where showing p0201 dtc? As always thanks for the videos. 🍺🍺

[@romanosautomotive]

Thanks for the support again Aldi! I've had the Autel for a very long time. It's great but nothing beats the overall functionality of the Snapons. That page at the end is from my data provider which is Autodata in Australia

[@mrbissi9377]

Hi Im having some issues with injector 6 circuit malfunction. After investigating and replacing spark plugs, coils. It still happens intermittently. A bit more investigating i have found when i lightly move the the bottom harnes on ECUi can replicate the injector 6 malfunction error. I have had a p0443 evaporative emission malfunction for about 2 years or so but still drivable and didnt have any issues. At present the car is still drivable and only notice is car rough idle for less than a minute and goes away. This only happens intermittently sometime doesn't happen for 300k. The car has 435000km These are the errors i have cleared in the past. The last 3 errors are more regular P0443-00 - Evaporative Emission Controll System Purge Solenoid Circuit Malfunction 18 - (Current) ECC Fault Logged 18 - (Current) Auxiliary Serial Data Bus Fault U2100-00 - CAN-Bus Circuit Malfunction 19 - (History) EEPROM Error U2108 (histroy) Can-bus No Communication with ABS/TC/ESP U2106 - CAN-Bus No Comunication with TCM (Transmission Control Module) P1632-48 Immobiliser Fuel Disable Signal Received p2500-00 - Alternator L terminal Low voltage p0206-00 - Injector 6 circuit malfunction p1668-00 - Alternator L Terminal circuit malfunction Has anyone had similar and was it a ecu. Should I go for 2nd hand or new? Thanks for your help

[@helenellsworth9556]

I got a feeling that's what's wrong with mine, new subby btw, 07 vz

[@romanosautomotive]

Thank you Helen, did you get yours fixed? Sorry for the late reply.

[@helenellsworth9556]

@@romanosautomotive I haven't fixed it yet, I did my front struts and the engine started to behave, I'm scratching my head of course 😬 the struts were absolutely recked

[@romanosautomotive]

It could be the magic fix haha. Well good luck and hopefully it stays fixed. Thanks Helen!! :)

[@d.d4184]

Nice Rob. What do you think was causing the high resistance when cold? A crack in the coil or soldier?

[@romanosautomotive]

D. D not sure to be honest, certainly could have been. I still have the injector, I should pull it apart. If I find something, I'll reply to this comment and let you know!

[@d.d4184]

@@romanosautomotive Thanks Rob. Not sure myself. When I see M ohm's on something with a coil {when hot} I always picture this as the coil or soldier expending like in a light bulb filament and loosing continuity,and a cold issue as the solider or coil shrinking and causing the same issues. Rant over.

[@DJ-tn7vj]

Yo Rom, this would be a great test for the GTC 605.the Injector tester

[@romanosautomotive]

I contacted GTC a week or so ago about the 605 but no response. If I end up getting one, I'll definitely do a review on it.

[@styeekiller250]

Rob - Pease explain the load pro hook up when injector tested

[@romanosautomotive]

The Loadpro isn't in use here. It's just a normal meter lead when the button isn't pressed. The Loadpro leads stay on my meter full time so there's no funky business going on 😁

[@DJ-tn7vj]

@@romanosautomotive yeah rom.loadpro stay attached.

[@holdenfan4513]

I've got the same code coming up on my 2005 vz sv6 and its doing the same thing . Misfires when cold then fine when hot I just changed cylinder 1 injector with a brand new one and its still exactly the same. Any suggestions could the new one be faulty or should I change the crank angle sensors

[@romanosautomotive]

Hard to say without seeing it Holden Fan, sorry.

[@holdenfan4513]

@@romanosautomotive all good man. Cheers for the reply

[@georgepatuaka391]

You just like a great mate of mine , I’d put my $$$ on you all day , mate rates of course and I’ll help you 👍🏾never to old to learn , Ol skool 👍🏾

[@romanosautomotive]

Haha thanks George

[@ivandrago2557]

Beside videos, there is always mine type of music in workshop

[@romanosautomotive]

Thanks Ivan. My favourite radio station is always on in the background!

[@ivandrago2557]

Good radio station

[@DanWallis86]

You would have to be spewing if you bought an ecm when it was just an injector.

[@romanosautomotive]

Too right, definitely an expensive guess

[@theGADGETSplaylist]

6 coils + ECM over a bad injector, that's awful!

[@romanosautomotive]

Too right Denis! I think they got misled by the "control fault" terminology in the code description. Great to hear from you💪

[@richardcranium5839]

steering wheel is on the wrong side !!!

[@romanosautomotive]

haha next time I'll mirror image the video so its back on the correct side ;)

[@richardcranium5839]

@@romanosautomotive lol