Dismiss Notice

Welcome To CK5!

Registering is free and easy! Hope to see you on the forums soon.

Score a FREE t-shirt and membership sticker when you sign up for a Premium Membership and choose the recurring plan.

ALDL flash decoding....HELP....

Discussion in 'The Garage' started by heavy4x4, Mar 21, 2003.

  1. heavy4x4

    heavy4x4 1/2 ton status

    Joined:
    Aug 28, 2002
    Posts:
    3,270
    Likes Received:
    0
    Location:
    Delafield, Wisconsin
    Okay, a little background; a while back my SES light would light on the freeway for a few seconds then go off. Now, it's going on much more often. I don't notice any weird driving characteristics on the freeway, but once I get off, my truck idles at a "lopey" or unsteady 600rpm. So, I did the paperclip thing in the ALDL and got code 12 (flash--flash,flash) and then I got two more codes after that flashed three times. BUT for the life of me, I can't find in any of my manuals where these flash codes are given. I know what the various codes #'s mean, but I don't know what code numbers correspond to the flashes I'm getting. Here they are:
    (Flash---Flash, Flash, Flash)
    (Flash---Flash, Flash, Flash, Flash, Flash)
    Could someone please tell me what code numbers these are - that'd be much appreciated.

    THANKS.
     
  2. Itali83

    Itali83 1/2 ton status

    Joined:
    Feb 12, 2001
    Posts:
    795
    Likes Received:
    0
    Location:
    Westbrook Maine
    Code 13 is oxygen sensor circuit. SO I would check your wiring for that, it may be grounding out or becoming open intermittantly. It takes 5 minutes at part throttle for this code to set, which makes sence becuaes you said it did it while going down the high way.

    Code 15 is Open coolant sensor circuit, this code takes 5 minutes of the engine running for it to set. Hope this helps out. I would also check the wiring to make sure it is getting the 5v reference volage and make sure the signal wire going to the computer is good. Good luck@!!!
    Ben 87 Jimmy + 89 Blazer
    /forums/images/graemlins/usaflag.gif
     
  3. Shorts

    Shorts 1/2 ton status

    Joined:
    Oct 16, 2001
    Posts:
    336
    Likes Received:
    0
    Location:
    CC & SA, Tx
    fyi, code 12 is a user interface code
     
  4. Itali83

    Itali83 1/2 ton status

    Joined:
    Feb 12, 2001
    Posts:
    795
    Likes Received:
    0
    Location:
    Westbrook Maine
    Yea code 12 stands for "no distributor reference" If you don't get that three times and the first code you get, your computer is F'd.
    Ben 87 jimmy + 89 Blazer
    /forums/images/graemlins/usaflag.gif
     
  5. Thunder

    Thunder 3/4 ton status

    Joined:
    Jul 20, 2000
    Posts:
    8,946
    Likes Received:
    1
    Location:
    Northeast Nevada
    A bad coolant temp sensor will cause both codes 13 and 15 to be set.
    The bad CTS(code 15) will cause a rich F/A mixture. This will cause carbon to stick to the O2 sensor making it throw a code 13
     
  6. heavy4x4

    heavy4x4 1/2 ton status

    Joined:
    Aug 28, 2002
    Posts:
    3,270
    Likes Received:
    0
    Location:
    Delafield, Wisconsin
    Well, thanks a lot everyone. Itali83, where did you find a cross-reference for flashes and code numbers?
    I replaced the temp sender and tried to replace the O2 sensor also. The O2 sensor is STUCK so that'll have to wait or maybe never get changed. /forums/images/graemlins/ignore.gif
    The service engine soon light hasn't gone on since replacing the temp sender - so I think all is good now. Thanks for your help.
     
  7. Itali83

    Itali83 1/2 ton status

    Joined:
    Feb 12, 2001
    Posts:
    795
    Likes Received:
    0
    Location:
    Westbrook Maine
    I'm going to school at Nashville Auto Diesel college right now, I was in a computer diagnostics class abouta month ago and my school book had a lot of codes in it for me. SO I took them out of that book. As for the O2 sensor being stuck, and the new Temp sensor changing how much your check engine light comes on, I would change it, becuase it very well could be covered with carbon or just old and dead, giving your computer a false reading.
    On my jimmy I had to get a torch and heat up the manifold and then I was able to break the sensor loose. Once you do that, you'll most likely need to get a O2 sensor tap (it's actually a spark plug tap, same threads) and tap the bung because the threads will be all junky and not good. Then once you tap it, put the new sensor in and you'll be a happy camper. But if it's been in there long enoug to completely freeze in, it's time to replace it. Good luck
    Ben 87 Jimmy + 89 Blazer
    /forums/images/graemlins/usaflag.gif
     
  8. Shorts

    Shorts 1/2 ton status

    Joined:
    Oct 16, 2001
    Posts:
    336
    Likes Received:
    0
    Location:
    CC & SA, Tx
    a chilton's manual has them all listed too
     
  9. Thunder

    Thunder 3/4 ton status

    Joined:
    Jul 20, 2000
    Posts:
    8,946
    Likes Received:
    1
    Location:
    Northeast Nevada

Share This Page