Newest Gallery Photos

  1. Chevy Truck Forum

    Welcome To!

    The #1 Chevy Truck Forum Online

    Online since 2004, we're the #1 Chevy Truck & SUV user community. If you have any questions about your Chevy or GMC Truck, SUV or Crossover, or just want to connect with other GM owners and enthusiasts around the world, you've found the best place on the internet to do that.

    Join Today ~ It's Free

    Registering is Free and Easy! Do it today and we'll see you on the forums soon!

Messed up

Discussion in 'General Chevy & GM Tech Questions' started by brickborn, Feb 24, 2011.

  1. brickborn

    brickborn New Member

    I hooked my battery up backwards on my 1990 gmc suburban . Now I don't have spark or fuel ECMB fuse was popped and ECMB1 was also ,replaced ECM1 and it stayed ,replaed ECMB and it popped again ,checked one fuseable link by starter ,checked 2 or 3 up top. Nothing! Can anyone help???
  2. silveradotrailblazer

    silveradotrailblazer Epic Member 5+ Years ROTM Winner 5000 Posts

    Welcome to the club. You may have burned up the trucks ECM.
  3. stephan

    stephan Rockstar 4 Years 5000 Posts

    Welcome to the club Brick. Sorry I've never done that so I can't help you, but someone will be along that can. The closest experience I had was when my mom jumped her car backwards. It burned out the exciter diode in the alternator, but it still started & ran ok, (EFI) it just didn't charge. If your alt light in on when you get it up & running, then just repl the alternator cuz doing the diode is a PITA.
  4. 2COR517

    2COR517 Epic Member 5+ Years 1000 Posts

    You probably toasted the PCM, at the very least. None of the manufacturers put reverse polarity protection on the computers.
  5. mfleetwood

    mfleetwood Rockstar 4 Years ROTM Winner 5000 Posts

    Wow..sorry to hear the news. I hope you are able find out all that was damaged quickly and it doesn't cost you an arm and a leg to fix. Please keep us posted.
  6. dualdj1

    dualdj1 Rockstar 100 Posts

    probably best off checking with junk yards and see if you can find a used PCM
  7. Chris Miller

    Chris Miller Rockstar 100 Posts

    I second that. It doesn't take very much juice at all of the wrong polarity to fry one of those.
  8. 2COR517

    2COR517 Epic Member 5+ Years 1000 Posts

    PCMs are pretty cheap at AutoZone. I'll get you a price later.
  9. 2COR517

    2COR517 Epic Member 5+ Years 1000 Posts

    Cardone Reman should be well under a hundred bucks from AZ.
  10. brickborn

    brickborn New Member

    Hey Thanks for all the info . Still on same situation.still down . Checked everything even changed ECM with the one from my 89 and changed chips to match .same . Have power to coil and power to injectors but no spark and injectors won't fire.things I checked ,coil ,ignition module,fusible links , esc, the only thing left that im not sure about , is it possible for me to have fryd the chips that plug into the computer???any other suggestions or info greatly appreciated

Share This Page