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Unplugged ecm and now it wont start

Discussion in '3rd Gen Tundras (2014-2021)' started by 904Tundra4x4, May 1, 2021 at 11:13 AM.

  1. May 1, 2021 at 11:13 AM
    #1
    904Tundra4x4

    904Tundra4x4 [OP] New Member

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    I unplugged my ecm and after about 10 minutes my radiator fan came on so i plugged it back in. Now the truck wont start. Any ideas?
     
  2. May 1, 2021 at 11:18 AM
    #2
    tttrdpro

    tttrdpro Former Naval Person

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    Unhook the negative terminal on your battery for 10-15 mins. Hook it back up and give it a go.
     
    Saltyhero13 and 15whtrd like this.
  3. May 1, 2021 at 2:38 PM
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    Txexplorer23

    Txexplorer23 New Member

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    Wut.. did you this with power on? And why
     
  4. May 1, 2021 at 2:41 PM
    #4
    T-Rex266

    T-Rex266 Independentoffroad who? That's cute. Staff Member

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  5. May 1, 2021 at 3:06 PM
    #5
    904Tundra4x4

    904Tundra4x4 [OP] New Member

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    I forgot to unhook the battery. I did disconnect afterwards for almost 3 hours and still not turning over. Could this possibly have fried the starter
     
  6. May 1, 2021 at 3:09 PM
    #6
    Black Wolf

    Black Wolf Got RF/Microwave? CALIT4U

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    Zone UCA's, Fat Bob's Vated, Pro Form Fab shackles, Patagonia M/T's, Ranch Hand Grill Guard, RC steps, SDHQ AIP relocation kit, RetraxONE MX, Jomax ABS armor
    Curious. What was initial reasoning to disconnect the ECU?
     
  7. May 1, 2021 at 3:12 PM
    #7
    904Tundra4x4

    904Tundra4x4 [OP] New Member

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    I was mounting a shelf for a compressor that my buddy made and it was going over the top of it. It was having clearance issues and i unplugged it before realizing i didnt unhook the battery
     
    Black Wolf likes this.
  8. May 1, 2021 at 6:02 PM
    #8
    ejes

    ejes New Member

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    Have you checked all your fuses?
     
  9. May 1, 2021 at 6:19 PM
    #9
    904Tundra4x4

    904Tundra4x4 [OP] New Member

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    Yea both fuse boxes were good
     
  10. May 1, 2021 at 6:29 PM
    #10
    landphil

    landphil Filthy. Stinkin’. Rich. Two outa three ain’t bad.

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    Did you add an electric cooling fan to your Tundra? I’m having trouble understanding how a belt driven fan came on after ten minutes if the engine won’t start.

    With the battery disconnected, check for any bent pins on the ECM / damage to the connector and then make sure it’s fully locked together. Reconnect the battery, and try it again.
     
    nixon, JimboSlice413, 15whtrd and 2 others like this.
  11. May 1, 2021 at 6:34 PM
    #11
    ejes

    ejes New Member

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    Do the dash lights all come on? If so, it could be the ECU lost the immobilizer key codes.

    I agree with Phil. X2 and X3 check all your connections that you disconnected to make sure., and try again.
     
  12. May 1, 2021 at 6:41 PM
    #12
    904Tundra4x4

    904Tundra4x4 [OP] New Member

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    The dash lights come on. Its still the belt driven fan. Ill check the ecm pins tomorrow
     
  13. May 3, 2021 at 5:52 PM
    #13
    904Tundra4x4

    904Tundra4x4 [OP] New Member

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    Problem solved. It somehow blew my starter. All is well now.
     

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