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Flashing Check Engine Light

bdm62987
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bdm62987 Enthusiast

bdm62987

Posted
Posted

I was driving my 2016 Silverado 5.3L to work this morning going 72mph on the highway and the check engine light decided to start flashing for about 8 seconds and then shut off. The truck never lost power and nothing happened. I drove all the way to work and have been driving in the past with zero problems. Is this something I should be concerned with?

Justin101714 Enthusiast

Justin101714

Posted
Posted

Flashing light is when the ECM determines that there is a rise in emissions that could damage the catalyst, a misfire could cause this. Probably had a AFM lifter that got stuck open for a bit. If it happens again I'd worry about it then.

 

 

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muddkatt Senior Enthusiast

muddkatt

Posted
Posted

Carry it to your dealer and have them check the codes, then repair as needed.

  • Like 1
dasimmon Enthusiast

dasimmon

Posted
Posted

Flashing light is when the ECM determines that there is a rise in emissions that could damage the catalyst, a misfire could cause this. Probably had a AFM lifter that got stuck open for a bit. If it happens again I'd worry about it then.

 

 

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+1

Justin101714 Enthusiast

Justin101714

Posted
Posted (edited)

Go ahead and take it to the dealer then....if it isn't currently doing it, they're sending you out the door with a "no problem found" diagnosis.

 

 

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Edited by Justin101714
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16LT4 Enthusiast

16LT4

Posted
Posted

Codes are saved from in ECM memory and can be retrieved. If nothing else, take it simply for CYA so if your engine eats itself later on there is a record of complaints.

  • Like 1
LSR Mike Enthusiast

LSR Mike

Posted
Posted

When that happens I hit the OnStar Button...

Thomcat Senior Enthusiast

Thomcat

Posted
Posted

They should be able to retrieve the code provided you have an OnStar subscription.......they read the active code once when my evap.canister vent crapped out on a Tahoe.....they can access the vehicle for a remote start or monthly readout of problems so they should be able to do it for a stored code.

TxTruckMan Senior Enthusiast

TxTruckMan

Posted
Posted

Codes are saved from in ECM memory and can be retrieved. If nothing else, take it simply for CYA so if your engine eats itself later on there is a record of complaints.

Exactly. A tech can read the stored code. Maybe it's an intermittent problem that they can address. Maybe there's a TSB on the problem and they can perform a SW update. Either way, I'd just take it in for a quick look. They'll probably find nothing, but this is one of those "better safe than sorry" situations.

  • Like 1
  • 3 years later...
DaveJohn New Member

DaveJohn

Posted
Posted

Had flashing engine light, truck running rough, traction control light also on.  Definitely misfiring.  Took to dealer, code P0300, number 4 cylinder misfiring. ignition coil wire off, wire and coil corroded replaced same, all good

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