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07 duramax will not start

Discussion in 'Chevy Trucks' started by kelley5100, Jan 15, 2012.

  1. kelley5100

    kelley5100 Junior Member
    Messages: 9

    I have a 07 2500 Duramax that will not start when it get cold. It throws a code that says service anti theft system. My dealer replaced the security module and ignition switch. Dealer sad truck started right up,then parked truck out side and let set for 3 hours and would not start. It throws the same code again, service anti theftsystem. The only thing I did before this all started was to plug in block heater. Truck has 50K miles on it and has been awsome till this all started. Any ideas as to how to fix?
  2. Milwaukee

    Milwaukee 2000 Club Member
    Messages: 2,180

    It out warranty? Had they test key and key ignition?

    Can you turn on and wait 5 mins then try start.
  3. tuney443

    tuney443 PlowSite.com Addict
    Messages: 1,847

    I think your code is just coincidental with your engine not starting.Is it possible you might have gelled up or you just got a bunch of dirty fuel on an already almost plugged fuel filter? What have the temps been there lately and do you use an anti gel/ fuel treatment on every tank?
  4. RepoMan1968

    RepoMan1968 Senior Member
    Messages: 439

    seems to me the dealer still owns the problem. does it crank

    Last edited: Jan 15, 2012
  5. kelley5100

    kelley5100 Junior Member
    Messages: 9

    Not a fuel problem. When you turn key on nothing happens, no crank , no glow plugs, no gauges just message saying service Theft Deterrent System. Truck is still in warranty and dealer is at a loss as what to do? His next step is to call Tec Support at GM. Like I said earlier when truck is inside ,starts perfect. I have new fuel filter and good treated fuel.Same fuel in other trucks, no problem!!!
  6. tuney443

    tuney443 PlowSite.com Addict
    Messages: 1,847

    Have your batteries been checked?????It might sound too easy but having had 3 Dmxs,weak batteries will cause some strange stuff to occur.The only other thing I'm thinking remotely is when you plugged in your block heater,if you did'nt leave it on for at least 4 hrs. sometimes you can throw a code and screwy things can happen.GM advises not to plug in at 0* or higher.