2002 5.3L Check engine light flashing

[Bonecollector]

Hey question for the guys with the 1999-2002 5.3L what does the flashing Check engine light mean? I know it has the message centre that displays when it needs help but can't find the flashing CEL, it went out shortly after, I'm assuming cuz its a bit cold the O2 sensors may be not used to it, don't know for sure tho


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[19trax95]

Usually a flashing light mean something major and to stop right away.

There should be a code stored if it was on so without that code, diagnosis is anyone's guess

 

[Bonecollector]

Light came on for a short time and stopped right after, I'll need to scan it, hadnt run it for a couple of weeks and it was -16*C when I started it


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[Bonecollector]

Read somewhere a flashing CEL is a misfire


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[19trax95]

It could be. But I don't think that's the only thing.

I had a po300 code and it would flash the service engine soon (ses) Light.

But not the check engine. Usually the check engine is more serious than the ses

 

[Bonecollector]

I drove it all day no issues, no problems accelerating or idling, probably just because it was cold today and I havent run it a while, going to be plugging it in from now on


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[Bonecollector]

I will be scanning it when I get home, didn't feel like it had any issues driving


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[ichevy.rider]

Manifold intake gaskets maybe? Once it warmed up the gaskets may have expanded and created a better seal thus turning the cel off.


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[Bonecollector]

It has not come back since the cold starts, seems to be fine now


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[squeaky3]

Put a scan tool on it. I bet it was a misfire code stored. The light will flash to tell you to stop driving or damage to the cat can be possible.

The check engine light and service engine soon light is the same thing, just different name.

 

[Coyote56]

I have an '03 4.3L, on that the flashing check engine light just means a mis-fire.

 

[Bonecollector]

Probably was misfiring cuz it sat for a while and cold started without being plugged in, it only happened twice
Plugged in all the other days it was cold and no reoccurrence


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[moremilon12]

It means A blinking light usually indicates a severe engine misfire allowing unburned fuel to be dumped into the exhaust system.