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Thread: upgrade OS

  1. #1
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    Default upgrade OS

    I want to up grade my 02 chevy truck OS to an 2003 Chevrolet Express Van Automatic. I couldn't find a wire diagram to compare to. I know the pcm will need to be upgrade to 1MB pcm. Did they change the pin configuration in 03 pcm? Thanks for the help.
    2006 Trailblazer SS
    Twin Turbo 67 Chevy Truck
    SOLD Truck 2002 Chevy kb turbo t70 5.7l

  2. #2
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    Quote Originally Posted by aaronr View Post
    I want to up grade my 02 chevy truck OS to an 2003 Chevrolet Express Van Automatic. I couldn't find a wire diagram to compare to. I know the pcm will need to be upgrade to 1MB pcm. Did they change the pin configuration in 03 pcm? Thanks for the help.
    The 2003+ LS1-B have Blue / Green PCM connectors - the main difference is how the O2 sensors are pinned / controlled. If this PCM / OS change is to address your A/C issue - it won't help.


    Regards,
    Taz

  3. #3
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    Taz,
    So I assuming you read my other thread about how i add the a/c pressure sensor to my truck to help control my fans. Why don't you think the upgrade os wouldn't help me?
    Thanks
    Last edited by aaronr; May 12th, 2012 at 03:12 PM.
    2006 Trailblazer SS
    Twin Turbo 67 Chevy Truck
    SOLD Truck 2002 Chevy kb turbo t70 5.7l

  4. #4
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    In post #1 you indicate not having schematics for the proposed PCM pinouts - which means you are working without an OEM quality manual(s) or DVD of some sort - these are a necessary resource.

    GM used several different A/C control systems with the LS1-B PCM - the Express / Savana systems (all Gen III) are similar to your existing system - which does not work correctly with an A/C pressure sensor.


    Regards,
    Taz

  5. #5
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    Taz,
    What is the best way to set up these fans to get what looking for then? Thanks
    2006 Trailblazer SS
    Twin Turbo 67 Chevy Truck
    SOLD Truck 2002 Chevy kb turbo t70 5.7l

  6. #6
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    Posting in your original thread ... no sense in having two threads going for the same issue ....


    Regards,
    Taz

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