"Reduce Engine Power" warning light..

Discussion in 'Maintenance' started by bshattuck87, Dec 27, 2011.

  1. bshattuck87

    bshattuck87 GMFS Member

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    Hey everyone, I was driving along today and we were doing about 60mph. All of a sudden my truck lost 'power' and a "reduce engine power' message came up on my cluster. Of course the CEL came on as well. So I pulled over and shut the truck off. Turned it back on and no CEL and ran fine. I can't pull the code if the CEL isn't actually on now. I just put some AC Delco iridium spark plugs, AC Delco Spark Plug wires, and a new fuel filter on about a month ago. So I truthfully, I don't believe they are the culprits. I think if I could of pulled the code today when it happened, I would of got a random cylinder misfire code.

    However, has anyone else have this problem, or?

    Brenton
     
  2. Mortiz

    Mortiz Formerly TrucknGolf

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    Mine did that once. Just once and never again yet
     
  3. Samuel6731

    Samuel6731 Cant Get Right

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    i had a buddy that this happened to, not saying this is your problem because it could be multiple things.
    His truck went into REP mode every now and then, then got really bad like 3 times a day then got to where he couldn't drive it.
    After spending all kinds of money on different parts because it was throwing all kinds of different codes, come to find out the ECM ground wire had come loose and wasnt getting a good connection making the ECM throw all kinds of false codes
     
  4. ezskanken

    ezskanken GMFS Member

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    I have a feeling about this one for my own reasons,im checking it out tomorrow...
     
  5. bshattuck87

    bshattuck87 GMFS Member

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    Now that I think about it, this also happened about 2 month ago. It kinda sucks though that the CEL won't stay on so I can get a code reader on it real quick. Is it possible for a knock sensor to cause this?

    I don't know if this is related or not, but I installed the spark plugs/wires/fuel filter to help with my MPG. Since I've owned the truck, I've never got over 9MPG no matter how easy I drive it, and I was reading that the knock sensor's sometimes cause poor fuel mileage.
     
  6. bigblue4x4

    bigblue4x4 GMFS Member

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    a knock sensor will turn the SES light on and reduce the power since the computer wont advance any timing,but will not say "reduce engine power" in the msg center

    reduced power mode is when you over heat and the engine shuts down cylinders to air cool the engine
     
  7. Ginger

    Ginger kissin hands shakin babie

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    mine has done it twice in the 2 years ive owned it, just does it randomly but since its once a year, i dont pay much attention to it
     
  8. mmrkustoms

    mmrkustoms Friendly Funeral Director

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    might me your tb have put one on 2 03 5.3 burbans and a 6.0 3500 van
     
  9. theholycow

    theholycow AllOffTopic.com FTW!

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    Are you sure you can't get codes? Even my $40 Harbor Freight code scanner can get stored codes when the CEL is not currently on.

    It sounds like you own a scanner; maybe leave it plugged in all the time and grab the codes while it happens?
     
  10. GCncsuHD

    GCncsuHD ΜΟΛΩΝ ΛΑΒΕ

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    Yes you can....It should be stored.
     
  11. Ginger

    Ginger kissin hands shakin babie

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    mine would say for a code, the TBS is bad, but what would actually happen is i would be putting a big draw of power and it could surge the system.
     
  12. SSneaky6.0

    SSneaky6.0 Bag Envy

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    Happened to me once...cleaned the TB because it was disgusting and it's never happened again.
     
  13. DesertChev112

    DesertChev112 Formerly flipskater46

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    And ya dont assume the ECM off the bat. In my experiences it rarely is ever the ECM.
     
  14. Samuel6731

    Samuel6731 Cant Get Right

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    Very true. But still can happen and most will over look that.

    Sent from my I897 using Tapatalk
     
  15. iscrape

    iscrape so fa-coügh

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    Mine did this and it was the yellow wire in the plug that goes to the TB on the pass side. That wire commonly breaks inside the insulation. And you can see it visually. Hope this helps. Its a manufacturer defect.
     
  16. dagdillinger

    dagdillinger New Member

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    Re: "Reduce Engine Power" warning light.. 2007 Silverado 4.8 LT

    I have had issues with my truck getting the reduced engine power when I have my AC running for a while and sometimes not at all. I did research and found out that it can be either the throttle body, throttle position sensor, throttle position sensor connector, and coolant problem. From gm website it says that it occurs if engine gets to hot n needs to shut down part of the motor to prevent engine problems. Unfortunately fuel is not burning n ruins motor oil n needs to be replaced (oil change). I completely flushed my radiator, changed thermostat, replaced hoses, did a tune up (spark plugs and wires), Cleaned throttle body with cleaner, and STILL I get the message from time to time, but running the AC. My wires have been replaced as well for the TPS sensor. Has anyone done or come across the same thing? Suggestions..
     

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