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Will trouble codes show after check engine light is off?

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by Blazinaire, Jun 13, 2002.

  1. Blazinaire

    Blazinaire 1/2 ton status

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    I have an '87 K5 with TBI 350. Last night my motor died and the check engine light came on, then the truck restarted itself (it was still coasting down from about 65) and the check engine light turned back off. My truck has been acting up alot lately and I have made many other posts about these problems. My question now is, where is the part of the computer that I can do the "paper clip" check for trouble codes at? And, will the codes still show even after the engine has been restarted and the light has gone off. I'm pretty sure that I understand the whole bridging ports A & B, and then watching the check engine light flash thing, but where is the computer actually at? Please help, this is my daily driver and it hasn't been too reliable lately.
     
  2. MudNurI

    MudNurI 1/2 ton status

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    I don't know where it is- BUT I do know that they store the codes. Well, I know new truck store codes. When my Duramax went into LIMP mode, it stored the code, for 7 days before I got to the dealer...Isn't usually the SES light on older rig's the 02 sensor gone bad? I didn't think they had elaborate computer systems, just a light for 1 thing sort of system? Could be wrong...

    Brandy
     
  3. MudFrog

    MudFrog 1/2 ton status

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    Correct me if I'm wrong, but I believe the codes are stored untill the computer is reset.
     
  4. 91K5

    91K5 1/2 ton status

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    The connecter to jump the wires to show the codes in my '91 is located under the dash below the steering column. Its a little plastic connector thing with a few wires coming out the back, its easy to find. You may or may not have codes depending on what caused it to die. Since the engine died the ignition was on and the computer noticed there was no oil pressure and the engine wasnt running so it could have just lit to let you know, just like it does before you start the engine when the keys on.
     
  5. kilroy

    kilroy Registered Member

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    My 90 is same as 91K5, The computer will store the code if one was generated, for I think 45 starts, or until the computer is reset or until battery is disconnected.
     
  6. rampage

    rampage 1/2 ton status

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    They are stored in the computer until the battery is disconnected or 50 on/off cycles.
     
  7. Burbinator

    Burbinator 1/2 ton status

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    The check engine light will ALWAYS come on when the key is in the "run" position and the motor is off (stalled), provided the bulb is good. Turn your key to "run" and you'll see what I'm talking about.

    The light went off because there more than likely wasn't a problem when the truck started back up. If the light hasn't come back on, I'd leave well enough alone. I know this because my truck has done something similar.

    Also, look here for a comprehensive breakdown of codes.
     

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