In this video I bring you through my process of tracking down a misfire on this 3.8 liter Jeep Wrangler. The Pico Scope made it pretty easy to prove the fuel injector was at fault. Test don't guess!
-Enjoy!
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48 thoughts on “Jeep wrangler: p0204 injector circuit misfiring”
  1. Avataaar/Circle Created with python_avatars Rodd Cook says:

    I have a 2020 jk with a injector 3 misfire and injector 3 open circuit. I tested the injectors thru the harness and got pretty much the same results as the video. When cold jerp runs smooth as silk.

  2. Avataaar/Circle Created with python_avatars paul joey says:

    Wow

  3. Avataaar/Circle Created with python_avatars Braulio Ortiz says:

    Is there part 2 by any chance ?

  4. Avataaar/Circle Created with python_avatars Hortanium says:

    So what did it turn out to be?

  5. Avataaar/Circle Created with python_avatars Russ Treacy says:

    My wife's 08 Unlimited X is throwing FI codes (on injectors 1,2, & 3 per a buddy who used his reader). So I am in research mode. This video was helpful to look at possibilities.
    Now, it will have to wait until I am back home; can look at it face to face and use my reader.

  6. Avataaar/Circle Created with python_avatars Embermist69 says:

    Dealing with a P0201, don't have the labscope. However do have test light and a DMM. Cold the injector resistance matched a good one on the truck. Hot the good one went up a few ohms. (Matched factory service info specs.) The bad one wasn't able to measure with my manual range DMM and that's with making sure of pin contact. Set of six on the way. About near 190000 some odd miles. 07 Dakota.

  7. Avataaar/Circle Created with python_avatars Fred In Venice says:

    Very excellent. Good commentary on the Ohms Law references.

  8. Avataaar/Circle Created with python_avatars No Name says:

    could you lend me a hand and help me understand what circuit mean? You have Cavity, circuit and function. Cavity is obviously the connector. Its a map of what pin… goes where. it even shows you the connector. Circuit? I understand what the word entails but when using Mitchel on demand or all data, im lost. and obviously, function… again self explanatory

  9. Avataaar/Circle Created with python_avatars scott Drummond says:

    I know you not the sales guy. wish you listed what pico amp clamp. set up your using. great hands on learning.

  10. Avataaar/Circle Created with python_avatars Greg Armstrong says:

    Was the wiring diagram for that electrical plug possibly for a 4 cylinder model Jeep? I only saw 4 injectors listed instead of 6.

  11. Avataaar/Circle Created with python_avatars Mark Ferraro says:

    Lovin it EO

  12. Avataaar/Circle Created with python_avatars wingman778 says:

    Thinking about it. Makes sense to me. The fuel flowing through could have been just enough to keep it cool enough to function. The instant the fuel flow stops, it got hot enough to fail. Explains why it was able to run, then fail on queue.

  13. Avataaar/Circle Created with python_avatars Bobby Delamar says:

    Great diagnosis. How do you know the issue was down toward injector not ECM?

  14. Avataaar/Circle Created with python_avatars Go Clunker says:

    Chrysler should just have an engine is running correctly light. It would never come on

  15. Avataaar/Circle Created with python_avatars Go Clunker says:

    This engine is an abomination. I have a 3.8L caravan, no matter how many parts i throw at it, its never quite right. Compression? Perfect. New heads, valves, exhaust manifolds, gaskets, headgaskets, seals, all sensors, everything is oem mopar, injector harness, plugs, injectors, waterpump, literally everything is new other than the short block and it still does weird crap like a intermitted sputter. New cat and o2s too.

  16. Avataaar/Circle Created with python_avatars Brent Owen says:

    would an injector flow rate test help in this situation? thinking this at about 15.30

  17. Avataaar/Circle Created with python_avatars Mark McKelvy says:

    1, 2, 3, somethings missing, 5, 6.

  18. Avataaar/Circle Created with python_avatars Fast Turbo says:

    Great video like always thanks

  19. Avataaar/Circle Created with python_avatars zr1sparky1 says:

    Anyone in the troubleshooting game has had that happen to us but it's always more fun when it happens to the other guy haha!

  20. Avataaar/Circle Created with python_avatars Nigel Clark says:

    Good stuff.

  21. Avataaar/Circle Created with python_avatars Mohamed Ahmed says:

    Good to see you keeping up with technology and using the newest Pico software.

  22. Avataaar/Circle Created with python_avatars Alex Derus says:

    Why did the voltage scale on the scope have to be 100 volts? What's with that spike?

  23. Avataaar/Circle Created with python_avatars John Letch says:

    SO,what is the "money"light for us in the uk,please?

  24. Avataaar/Circle Created with python_avatars The Observer says:

    Hi, my honda accord 2014 vibrate while accelerating between 1000 and 2000 rpm, once it reaches above 2000 it drives normal. The local garage cleaned maf sensor and replaced spark plugs but still it vibrate, do you have any suggestions?

  25. Avataaar/Circle Created with python_avatars Kasual Skeptik says:

    Check for rat poop !!!

  26. Avataaar/Circle Created with python_avatars EthanMarcus Frishko says:

    anyone know what site he pulls all the diagrams and service data from?

  27. Avataaar/Circle Created with python_avatars Mark Zinsmeyer says:

    Eric, the thumbnail for the video is perfect. Looks like you came out with your new country music single titled " If She Ain't Broke".

  28. Avataaar/Circle Created with python_avatars H Christian says:

    That's just a Jeep making Jeep noises.

  29. Avataaar/Circle Created with python_avatars Chris N says:

    Another video sponsored by Chrysler.

  30. Avataaar/Circle Created with python_avatars Dale Kirkes says:

    Great teaching

  31. Avataaar/Circle Created with python_avatars Martin Steyn says:

    I'm in SA working on jeeps, the most common fault on them is 02 sensors but I've had alot of them with the same problem just close the lugs in the plugs a little the plugs wear out and then makes poor connection I've had two of them where the ecu was the problem, if that doesn't help try replacing the ecu"pcm" that should solve it

  32. Avataaar/Circle Created with python_avatars Justin Case says:

    Cool .. now you’re “trail rated” …

  33. Avataaar/Circle Created with python_avatars jack handy says:

    I'm a mother lover

  34. Avataaar/Circle Created with python_avatars LadyAnuB says:

    Reminds me of an intermittent fault on a fire alarm panel I was working on.
    Tried tracing out the wiring to no avail, including going into the attic to breaking the circuit there and seeing what happened. Everything was fine. Leave the place frustrated and with panel in proper operating condition.
    Go out again for same issue but this time notice the rat's nest wiring inside the panel and trace out the zone wiring where the problem was happening. Out of sheer past knowledge, I shake the wire, low and behold, I cause the fault. Now I know where the problem lies and I now go about shortening this wiring until I get past the iffy wiring spot.
    Sometimes you just luck into your problem.

  35. Avataaar/Circle Created with python_avatars Kevin Brewer says:

    Awesome use of the pico scope. If this doesn't make me want to buy one I don't know what will.. Thanks for that 😉

  36. Avataaar/Circle Created with python_avatars mark inkster says:

    It's a Chrysler, nothing EVER goes right!

  37. Avataaar/Circle Created with python_avatars Paul Schmied says:

    Eric may be right but . . . the wiring harness was disturbed by unplugging the connector.
    Most of the open intermittent circuit I've found were at the connectors, and sometimes they were not from corrosion on the contacts but poor connections to the conductors. I've found these even inside potted connectors
    Don't trust an automotive connector terminal crimp; it creates a stress point on newer terminals that don't also crimp to the insulator. Take 3 minutes and use a vampire connection to the inj4 lead to check continuity through to the connector pin before determining the problem is elsewhere. This would definitely point closer to where the open is. If the connection is solid, the injector coil or ITS connector is opening with heating, and when cooled closing and perhaps making a poor temporary weld.

  38. Avataaar/Circle Created with python_avatars Brian Bickley says:

    Cat person? Where's Chloe?

  39. Avataaar/Circle Created with python_avatars Travis says:

    lmao wife givin it away ur a cat guy :p its all good man any animal deserves some love

  40. Avataaar/Circle Created with python_avatars systemloc says:

    First time I've seen an intermittent fault that actually acts up right when you test it!! Lemme know when you want to hit Vegas. With your luck, I want to come with!

  41. Avataaar/Circle Created with python_avatars Dave Scruton says:

    I don't want to touch anything….finds connector, grabs it. Lol Eric.

  42. Avataaar/Circle Created with python_avatars Mike Phelps says:

    Why is channel B voltage scale at 100v?

  43. Avataaar/Circle Created with python_avatars Chris M. says:

    Learning is never a disappointment. 😉

  44. Avataaar/Circle Created with python_avatars Aleiyah collado says:

    i got to learn to use a scope…would save me having to take off that intake to check the injector

  45. Avataaar/Circle Created with python_avatars Aleiyah collado says:

    just got a pico and thought i would watch this for tips! Thank you , Eric for the video

  46. Avataaar/Circle Created with python_avatars BigM2446 says:

    You put out True Reality Tv. Thank you for that

  47. Avataaar/Circle Created with python_avatars Dave says:

    Great video!

  48. Avataaar/Circle Created with python_avatars Drew Duncan says:

    Forgive my ignorance, but what do you mean when you say you did “power brake it a little bit”?

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