In this video I have a look at a 2011 Chevy 2500HD 6.6 with the Allison transmission that would not shift. The local Chrysler dealer replaced the trans for other issues but ended up with this problem after the replacement. -Enjoy!
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49 thoughts on “Chevrolet 2500hd 6.6: allison transmission won’t shift p2669”
  1. Avataaar/Circle Created with python_avatars Josh Miller says:

    Hey bud I have a 2002 duramax with the allison just had a reman trans put in got the truck back ran great lots of power. Then i threw a code for torque converter solenoid took it back to shop a week later got the truck back and now there's no codes but truck has no power out of the hole feels like it starts out in 2nd or 3rd gear. you happen to have any clue.

  2. Avataaar/Circle Created with python_avatars Aquan Hodge says:

    💯🎯👊

  3. Avataaar/Circle Created with python_avatars Randy Tolin says:

    Good job dude I think you fixed it

  4. Avataaar/Circle Created with python_avatars Craig Williamson says:

    I have a 2006 2500 4×4 hd has the 8.1 vortec gas engine and Allison 1000 transmission i the reverse to work again but now it doesn't want to shift pass first gear what I'm i missing

  5. Avataaar/Circle Created with python_avatars Willard Kelly says:

    I have a 2008 Chevrolet 2500 with the 6-speed Allison Transmission has a slight vibration on downshift from 5625 524 other than that work flawlessly any ideas

  6. Avataaar/Circle Created with python_avatars joe smith says:

    mr o if it wasnt for GM u would be out of business!

  7. Avataaar/Circle Created with python_avatars Doug Shiner says:

    I have had a similar problem with Allison TCMs on a bus. Once I found that the pin locator (red plastic thing inside the TCM plug) wasn't seated, similar to what you found. The result was that the plug would not seat even if the securing screw was tight, and several pins didn't contact. Once I clicked it back into place, the plug seated the extra few mm and the fault went away. Still had other wiring issues with the transmission but that's a different story.

  8. Avataaar/Circle Created with python_avatars John Dickerson says:

    Sometimes it's really that simple. Last mechanic didn't plug it in rite. Great job 👏

  9. Avataaar/Circle Created with python_avatars Juliet Scott says:

    Lots of folks still be thinking there's no cure for herpes unless they never heard of Dr.Ahonle on youtube?

  10. Avataaar/Circle Created with python_avatars EDDIE LEAL says:

    By the sound of it could be a wiring harness issue. Corrosion within the trans circuit at the connectors or somewhere along the wiring harness.

    What Causes the P2669 Code?

    Damaged, corroded, open, or shorted wiring or connectors with any of the connected control modules
    Damaged, open, or shorted wiring or connectors in the ECM
    Loose or not connected ground wires to the ECM
    Loose or not connected ground wires to any other control module
    Damaged or defective ECM the TCM?

    What the P0700 code means
    P0700 is set when the PCM detects a malfunction in the transmission control system. This malfunction causes the vehicle to set a Check Engine Light and trigger a failsafe mode. Once the failsafe mode is set it will remain until the fault is repaired or normal operation is detected.

    What causes the P0700 code?
    Faulty transmission control module
    Transmission valve body fault
    Shift solenoid issues
    Open or short in the wiring harness

  11. Avataaar/Circle Created with python_avatars gokblok says:

    Poor Chrysler techs. If trans no worky, build it. If you can't build it, replace it.

  12. Avataaar/Circle Created with python_avatars Pat Jago says:

    Only way I could do it is if I have a video of you showing me how.

  13. Avataaar/Circle Created with python_avatars Longbar says:

    45 secs in i just said new loom.
    fingers crossed

  14. Avataaar/Circle Created with python_avatars Mike Beale says:

    Hate it when they fix themselves…makes me lose sleep..😒

  15. Avataaar/Circle Created with python_avatars Nick Loss says:

    His biggest mistake was taking it to a Chrysler dealer. In my experience the techs at Chrysler dealerships are the most incompetent I've ever seen. I've had a radiator, water pump, hoses, etc replaced because they couldn't find a leaking thermostat housing, currently been without my car for 6 weeks because they can't find the source of a misfire. So far they've replaced all fuel injectors, the PCM, and now the cylinder heads…

  16. Avataaar/Circle Created with python_avatars William Von Roenn says:

    I have this issue sometimes in my line of work… I always say it's not a problem if I can't replicate it… Mine is just camera work though…

  17. Avataaar/Circle Created with python_avatars Donnie Robertson says:

    Second time watching A+

  18. Avataaar/Circle Created with python_avatars Shane Harrison says:

    Well it ain't broke now dont fix it

  19. Avataaar/Circle Created with python_avatars Barnettj35 says:

    Does that sound plug just pull out?

  20. Avataaar/Circle Created with python_avatars Mice InOz says:

    I dunno, this seems to against the golden rule of "fix it till it breaks"

  21. Avataaar/Circle Created with python_avatars Donald Rackley says:

    Great video Mr owe

  22. Avataaar/Circle Created with python_avatars J. Decker says:

    Your diagnostic ability is second to none! Would you be interested in checking out some voting machines?

  23. Avataaar/Circle Created with python_avatars tonyfremont says:

    I wouldn't be too surprised if the old transmission was fine. Allison builds a fairly sturdy transmission.

  24. Avataaar/Circle Created with python_avatars jcnikoley says:

    Did you say Chevy "20-E-Lemon"?

  25. Avataaar/Circle Created with python_avatars Andy Clemente says:

    Great video. Where you get the wiring diagram from, besides using alldata and prodemand

  26. Avataaar/Circle Created with python_avatars Redskins Fan says:

    When ever I have a intermittent problem with tcm,ecm or I am not sure.
    I use a blow dryer to heat up what ever control module i am questioning.
    I works about 95% of the time to determine if good or bad.

  27. Avataaar/Circle Created with python_avatars James Valentine says:

    Best Tech 2?

  28. Avataaar/Circle Created with python_avatars James Boris says:

    you good

  29. Avataaar/Circle Created with python_avatars michael cummings says:

    At least the guy got a transmission out of it, Allison is freaking expensive

  30. Avataaar/Circle Created with python_avatars kenneth connors says:

    that Allison Transmission was made by Chevrolet

  31. Avataaar/Circle Created with python_avatars Old Gringo says:

    So did it live happily ever after?

  32. Avataaar/Circle Created with python_avatars Hola! Jerry Cherini says:

    Eric, Which case are you using on your surface pro? Thanks for all the effort you put in your videos.

  33. Avataaar/Circle Created with python_avatars Kevin Blackmon says:

    And terminal fretting may be the culprit bc GM harnesses and terminals are plagued with this issue. I’d rather poke my eyes out with a fork than deal with these kinds of issues

  34. Avataaar/Circle Created with python_avatars Kevin Blackmon says:

    I work on Duramax trucks every day. This is more common than u think. Unplug a connector, plug it back in and BAM everything works. It’s a nightmare. I’ve got an 05 that would not start. Codes for all 8 injector circuits and both Group circuits. Verified fuel to pump. Was leaning towards FICM. Started ohming wires from FICM to injectors and they all ohm perfect. Plug FICM back up, turn the key and she starts. Now I can’t get it not to start. Wiggle harnesses and wires and she runs like a top. So u wanna work on cars? Diesels? It’ll be fun. 🤔

  35. Avataaar/Circle Created with python_avatars Gale Gregory says:

    Another One Bites the Dust

  36. Avataaar/Circle Created with python_avatars David Voinier says:

    Guys like Neutral Drop provide entertainment, but the mechanic in me abhors the violence put to fine machinery that they do. I just shiver when I see one of their videos. It ain't right!

  37. Avataaar/Circle Created with python_avatars David Voinier says:

    I REALLY hate it when a vehicle fixes itself! Not really since you fixed it just by removing a connector and reconnecting it, but you know what I mean. Now, did it really need a transmission?

  38. Avataaar/Circle Created with python_avatars Joe L. says:

    At the very least , you need to be paid for your time , input and fix !
    You know the other place is charging ..
    Joe Navy veteran

  39. Avataaar/Circle Created with python_avatars Joe Vreeland says:

    If I had to pay for the education you've given me, I'd be broke. I
    'm relegated to working on friends' vehicles, and anything built after 2003 kinda scares me.
    But I just bought a new OBD2 scanner to supplement my old Snap-on brick —> which wont cover the newer stuff.
    I can only hope to recoup the money spent on it before I die (which may be any day now)
    Thanks ….. I think!

  40. Avataaar/Circle Created with python_avatars Donnie Robertson says:

    Second time watching 5/28/2020

  41. Avataaar/Circle Created with python_avatars Bill Vonkreuzhof says:

    I hope you increase your rate for dealership work ….. lol …..

  42. Avataaar/Circle Created with python_avatars R L says:

    I'd ship it tell if it acts up its probably going to need a trans module