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Tire size change alfaOBD

Discussion in '4th Gen DIY' started by Redheadhunter21, Nov 9, 2018.

  1. MTBryan

    MTBryan Junior Member

    Age:
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    Joined:
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    Location:
    Collierville, Tn
    Ram Year:
    2020
    Engine:
    Hemi 6.4
    I know this has been beat to death, but it still wasn't straight forward for me.
    I have a 2020 Power Wagon. I have a few notes (as a summary) and a question at the end.

    The CAN blocks were tricky to access on my 2020. They are behind the light switch. You can take off the kick plate with 2 7mm screws then pull. Take off the light switch assembly just by pulling hard on that sucker. You can take the plate under the light switch off too by pulling. I was able to get the CAN connectors in OK. But no way getting them out without taking the CAN blocks off their mounting location. Luckily they clip in/out easily. Once you loosen them, you can get a small screwdriver in there to remove the catch pins.

    Trying to clear some codes, I disconnected my battery. This completely wiped out all apps. So, my backup camera, air conditioner and satellite radio access icon were gone. I read they will come back on their own after the truck re-loads them. That's what happened! About 3 hours later, after much panic.

    I purchased the ODB Link MX+, AlfaODB app for my Android phone, and the Kaodtech bypass cable. Mike at Kaodtech was a HUGE help with my stupid questions trying to figure out where the CAN blocks were located.

    Once all hooked up, I followed the instructions on page 1 of this LOOOOONNNNNNGGGGGG thread. And overall it worked. It took about 6 times to get my circumference dialed in for my 35'. Ended up at 2688 mm.

    Now for the Question

    No matter what I do, I still get a C006A fault (access accelerator sensor) and cannot clear it. When I turn on the engine, both cruise controls are disabled (adaptive and regular) and it says the Stability control has been disabled and needs service. It also says the trailer brake system needs service.

    I've performed the resets on page 1 of this tread probably 30 times: Static ECU initialization and clear rolls information. I've done them with push start recycle and without. I've waited 5-10 minutes between cycling with no luck. I've tried other resets too like ECU. I disconnected the battery for 30 minutes: Still no luck. I've stood on my head on a full moon. No luck.

    I ended up taking it to the dealership today. they can't get to it for a week. Which is what they told me after a stern lecture (as I expected). Any additional help/thoughts would be greatly appreciated!
     
  2. MTBryan

    MTBryan Junior Member

    Age:
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    Joined:
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    Location:
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    Ram Year:
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    Engine:
    Hemi 6.4
    ...
     
  3. MTBryan

    MTBryan Junior Member

    Age:
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    Collierville, Tn
    Ram Year:
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    Engine:
    Hemi 6.4
    Update: I never got my cruise control reset. I had to make an appointment at the dealership. Somehow I deleted the module software for the trailer brake system and electronic stability control, which lead to the cruise control issue. They had to reset EVERYTHING to factory. Cost me $227 bucks and a lecture about using an aftermarket module.
    And after all that, they reset my tire size back to stock so my spedo is off again.
    So,
    $99 for the ODBLink
    $50 for AlfaODB
    $50 for the Kaodtech security bypass cable
    $227 to fix what I broke by trying to use the above.
    The dealership did say, for $120 they can change any settings I need (tire size/pressure). I will be selling my cable and ODB module and going that route next time.
     
  4. mtnrider

    mtnrider Senior Member

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    I find that extremely hard to believe. Unless you have a "buddy" there I have not seen 1 single dealer that will change the tire pressure settings, not 1. It is technically illegal to change or disable the TPMS (Tread act) so they are not going to go down that road.

    .
     
    G. Mcpherson likes this.
  5. loki223

    loki223 Senior Member

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    Location:
    Spokane, WA
    Ram Year:
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    Engine:
    Cummins 6.7
    So reading the last couple pages for changing tire sizes it seems like there are some issues currently? What are the current steps for Alpha? i have version 2.1.9.5 and am ready to change my size, but also don't want to brick anything or run into some of these issues, 2018 Ram 3500. Running the android variant of alpha
     
  6. CLeng3940

    CLeng3940 Junior Member

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    Ram Year:
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    Engine:
    3.6 Pentastar
    I changed my tire size and got no faults after backing out of the BCM and cycling my key. Didn’t even go into the abs. Has anyone else encountered this?
     
  7. MathanDubh

    MathanDubh Junior Member

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    Ram Year:
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    You have only done the first part. The numbers will display
    on the dash, but you'll still get a fault
     
  8. loki223

    loki223 Senior Member

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    I did the full procedure listed in post #1 and it worked. Verified with a GPS app on my phone that everything reads correctly, when before it was about 2 mph off
     
  9. UpInSm0kE

    UpInSm0kE Member

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    2019 Ram 2500 Tradesman
    Engine:
    6.7 Cummins
    Man, I think I just did this to my truck as well! 2019 Ram 2500, I changed my tire size to 2695mm with no issues at all but it was slightly off still so I went to change it again and now trailer brake system and service electronic stability control warnings are the only ones popping up. I cannot seem to clear these no matter what I do!
     

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