Think i messed something up
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HT4100 4.1, 4.5, 4.9 Discussion, Think i messed something up in Cadillac Engine Technical Discussion; I was checking my codes with car off. After i got into the diagnostic with "OFF" and "WARMER" buttons i ...
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    zentrade is offline Cadillac Owners Fanatic
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    Think i messed something up

    I was checking my codes with car off. After i got into the diagnostic with "OFF" and "WARMER" buttons i accidently pressed "HI" and saw some "E" codes and heard clicking under hood of car. Saw the ISC motor moving and then it stopped. car seems ok but smells raw fuel a little. What bonehead move did i just do and how do i check to see if i screwed anything up?....did i accidently make some adjustment?

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    HUF
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    Re: Think i messed something up

    Quote Originally Posted by zentrade View Post
    I was checking my codes with car off. After i got into the diagnostic with "OFF" and "WARMER" buttons i accidently pressed "HI" and saw some "E" codes and heard clicking under hood of car. Saw the ISC motor moving and then it stopped. car seems ok but smells raw fuel a little. What bonehead move did i just do and how do i check to see if i screwed anything up?....did i accidently make some adjustment?
    You probably entered override mode. Do not worry you could not hurt anything. Everything was back to preset values as soon as you turned ignition off.

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    zentrade is offline Cadillac Owners Fanatic
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    Re: Think i messed something up

    Wheeew! Thanks! I took car for a short drive this evening and just got in to check the posts...all seems ok with that...thx for reply!

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    awadecki is offline Cadillac Owners Enthusiast
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    Re: Think i messed something up

    Yes, you didn't do anything bad at all. I think that's either the override (as HUF said) or output cycling mode...in which case, the car started cycling all solenoids and computer controlled devices on/off like the ISC and also your EVAP purge solenoid which holds vaporized gas fumes and releases them when you drive and when the engine is warm (hence the gas smell--it's not supposed to open when the motor is off).

    That's just a normal procedure. Nothing to worry about.

    By the way, to find the throttle stop screw look where the throttle plunger meets the throttle body. You should see the end of a screw sticking out. You can adjust the other side with an offset torx wrench.

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    zentrade is offline Cadillac Owners Fanatic
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    Re: Think i messed something up

    Great, thanks! also can you tell me how i can calibrate the TPS? Have to replace mine, Im not sure about how to get the readings from onboard diagnostics to adjust it. If you could Dumb it down for me as much as possible step by step Much appreciated!

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    Re: Think i messed something up

    Quote Originally Posted by zentrade View Post
    Great, thanks! also can you tell me how i can calibrate the TPS? Have to replace mine, Im not sure about how to get the readings from onboard diagnostics to adjust it. If you could Dumb it down for me as much as possible step by step Much appreciated!
    If the car runs well, the power is there and the fuel economy is fine, I would not touch anything.

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    zentrade is offline Cadillac Owners Fanatic
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    Re: Think i messed something up

    Well, Its got an E27 code, Gas mileage if very poor right now. Not sure if the E27 is my ISC or TPS. Was going to replace both. Would like not to have to replace the TPS to be honest but whats the cause of the E27?

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    awadecki is offline Cadillac Owners Enthusiast
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    Re: Think i messed something up

    First of all, the root cause may be neither the TPS nor the ISC. If your gas mileage is poor, my first guess would be the EGR valve sticking open. What happens is that after about 60-80k miles, the valve starts to stick open. As a result, the computer compensates for this by increasing the idle speed (since a stuck EGR will normally slow the idle down). If it gets too bad, the computer can't extend the ISC plunger further at idle, and you'll get that code.

    So, as a test when the car is COLD (if you do it when hot, you'll burn your finger), remove your air cleaner and look for a rather large, circular, dome-like thingy that will be very close to the backside of the throttle body on the driver's side of the car. That's the EGR valve. Take your finger and push up on the underside of the valve. If it doesn't move freely, it needs to be replaced. That's where I'd look first with the bad mileage issue. Usually TPS sensors don't go bad--sometimes they're misadjusted, although your ISC could definitely be bad (not sure what E27 is). Nonetheless, check the EGR.

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    zentrade is offline Cadillac Owners Fanatic
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    Re: Think i messed something up

    Thanks! I actually checked the EGR valve not long ago (on a post i made about a disconnected EGR solenoid)It was fine then, Moved very freely, but i`ll recheck it.

    Here is something to add to the possibility the ISC switch is bad or going bad...I can recall a couple times i shut the car off and the ISC motor looked like it was going haywire...extending and retracting several times quickly..again with car completely shut off. Could that be an indication its on its way out or is that a normal move?

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    awadecki is offline Cadillac Owners Enthusiast
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    Re: Think i messed something up

    It is supposed to do this. It should move in and out about three times when the motor is shut off. This is normal.

  12. #11
    zentrade is offline Cadillac Owners Fanatic
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    Re: Think i messed something up

    Ok thanks!

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    awadecki is offline Cadillac Owners Enthusiast
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    Re: Think i messed something up

    Does your car have a rough idle? If so, with that bad of mileage, you might need a new fuel pressure regulator and/or fuel injector.

  14. #13
    zentrade is offline Cadillac Owners Fanatic
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    Re: Think i messed something up

    Idles like a dream!

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    daytona_dale_3 is offline Cadillac Owners Member
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    Re: Think i messed something up

    I'm not sure if replacing the isc or the tps is going to help you out. Heres what I found about your code. Unfortunatly, there's no t/s steps.


    http://myweb.accessus.net/~090/dtcobd1.html

    Hope this helps.

    Scott

  16. #15
    zentrade is offline Cadillac Owners Fanatic
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    Re: Think i messed something up

    Actually i replaced the ISC earlier in the week as the more and more i read, That E27 code pointed to the ISC not functioning properly and it was the easiest try and i got an ISC motor for not much....So i changed it and if problem persisted i would move to the TPS and consider the ISC replacement a spare part for the future if need be.

    So far (knock on wood) problem seems to be resolved.

    Thanks all for the help!

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