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Used a code scanner...now how do I resolve my problem?

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by MudFrog, Apr 19, 2001.

  1. MudFrog

    MudFrog 1/2 ton status

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    Ok... according to my code scanner... it flashed 4 pause 3. Which is 43. The manual says:
    Electonic spark timing (EST) circuit - low voltage detected.
    OR
    Electronic spark control (ESC) circuit problems.

    Does this mean I need to upgrade to a MSD ignition switch or something?

    89 K5 Silverado
    <A target="_blank" HREF=http://mudfrog.coloradok5.com>http://mudfrog.coloradok5.com</A>
     
  2. mattman

    mattman 1/2 ton status

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    My book says it is a problem with the ESC module which deals with the knock sensor circuit. The book I have is "How to repair and modify Chevrolet fuel injection" by Ben Watson. He gives pretty good diagnostics in there. I got it at Bookstop years ago but have seen the updated version elsewhere. If you check a local bookstore they might have it and you can read it and remember (my favorite way). Bottom line according to the book, the black wire on the ESC module on the intake manifold is going low voltage, and could be bad knock sensor, ESC module, or wiring connection between the ESC and the computer causing the computer to see low voltage. Mine use to do this all the time and then kinda stopped. Basically it was detonating and tripping the alarm. My engine has since deteriorated and doesn't except for when it backfires. Also, when this alarm trips, it retards the timing on the engine until you turn it off and on again and clear the check engine light. You'll notice a power drop whenever the check engine light comes on. I tried replacing the plugs twice but didn't do any good. Someone else on here might give more/better help but this is what I know firsthand. Also, I think the EST is for the TPI motors.

    90 GMC Jimmy, 350 TBI, 700R4, 32's
    84 Bronco II 204,000 miles and counting...........
     
  3. MudFrog

    MudFrog 1/2 ton status

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    k...well you just described what happens....but anybody know how to narrow it down and fix? Thanks for pointing me in the right direction mattman.

    89 K5 Silverado
    <A target="_blank" HREF=http://mudfrog.coloradok5.com>http://mudfrog.coloradok5.com</A>
     
  4. OFFRDK5

    OFFRDK5 1/2 ton status Premium Member

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    Before you go wire hunting...I would try reseting the computer...pull positive battery cable for about 30 seconds...just see if it comes back. I have had many problems with my S10 with codes being set and just unhooking the battery and reseting the computer helps alot.


    SK-15
    J**P...it's whats for dinner!
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    Roads? Where we're going, we don't need any roads!
     
  5. MudFrog

    MudFrog 1/2 ton status

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    I'll try that tonight... Thanks.. I haven't reset the computer since I bought the thing

    89 K5 Silverado
    <A target="_blank" HREF=http://mudfrog.coloradok5.com>http://mudfrog.coloradok5.com</A>
     
  6. mattman

    mattman 1/2 ton status

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    Sorry about the rambling - kinda whacked out on Actifed. I had tracked it out this far. Mine used to trip the check engine code at least 2-3 times a week on this and then stopped so I never finished tracking it out. My engine used to detonate a lot so mine could have been legit. Until I saw your post I hadn't realized it hadn't done it in a while. Don't know what happened - something burned out further, engine got better or the "ghost" went away.

    90 GMC Jimmy, 350 TBI, 700R4, 32's
    84 Bronco II 204,000 miles and counting...........
     
  7. MudFrog

    MudFrog 1/2 ton status

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    I disconnected the battery and it runs a little smoother now but I still get the check engine light.s

    89 K5 Silverado
    <A target="_blank" HREF=http://mudfrog.coloradok5.com>http://mudfrog.coloradok5.com</A>
     
  8. MudFrog

    MudFrog 1/2 ton status

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    I disconnected the battery and it runs a little smoother now but I still get the check engine light.

    89 K5 Silverado
    <A target="_blank" HREF=http://mudfrog.coloradok5.com>http://mudfrog.coloradok5.com</A>
     
  9. OFFRDK5

    OFFRDK5 1/2 ton status Premium Member

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    Take a look at the knock sensor area first. Check the knock sensor first..make sure it is hooked up properly.
    Thats about the extent of my help....

    SK-15
    J**P...it's whats for dinner!
    <A target="_blank" HREF=http://SK-15.coloradok5.com>http://SK-15.coloradok5.com</A>
    Roads? Where we're going, we don't need any roads!
     
  10. CV202

    CV202 1/2 ton status

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    Reset it and see if the trouble code comes back. If it does, take a look at your O2 sensor. Thats what gave me a 43 (in a round about way) It was running to rich and caused some detonation. A new O2 sensor did the trick. [​IMG]

    Why do people keep calling it a Bronco!!!!!
     

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