Blinking Check Engine Light

[egpilot13]

1100 miles on my 2020 Silverado RST 5.3L. 
Got blinking check engine light continuously for about 3-5 minutes while driving. It would temporarily extinguish when I pushed the accelerator. No associated messages or error codes. All engine parameters seemed normal. 
It stopped blinking and went away on its own. No idea. A bit disconcerting on a brand new truck though. 

[CamGTP]

There will be a history code stored, you'd have to scan it with a OBD2 code reader to see what it says.

[egpilot13]

Right on. Thanks for the response. I’m curious to find out. I drove the truck all day today. No blinking light. Keeping my fingers crossed. Still unsettling though. 

Edited October 7, 2020 by egpilot13

[Gangly]

Take it to autozone or a similar parts store and they will scan it for free for you.  A flashing check engine light is generally a misfire though.  Good luck!

[Colossus]

No notification from OnStar? 

[egpilot13]

I no longer have OnStar subscription. 

[egpilot13]

7 hours ago, Gangly said:

Take it to autozone or a similar parts store and they will scan it for free for you.  A flashing check engine light is generally a misfire though.  Good luck!

Didn’t know they did that. Will definitely stop by. Thanks! I hope you are right about the misfire. 

[Bobaloo22]

Our trucks are famous for the "misfire" code. If I nail it and hold it for a few seconds mine will do it some time.

[egpilot13]

1 minute ago, Bobaloo22 said:

Our trucks are famous for the "misfire" code. If I nail it and hold it for a few seconds mine will do it some time.

Interesting...I sure hope that was the case. My first Chevy. Don’t get me wrong. I love the truck. Just don’t want to be part of the horror stories I hear sometimes. 

[Bobaloo22]

The first time mine did it was when my truck was fairly new, it scared the crap out of me so I bought an OBD scanner. I would not worry about it, when it stays on then it can be more serious.

[Salsa De Piña]

2 hours ago, egpilot13 said:

I no longer have OnStar subscription. 

You may no longer have safety and security, but vehicle diagnostics is good for 10 years.  How else will they keep pestering you to go to the dealership for service?

[egpilot13]

Didn’t realize that. Will reach out to them. Thanks. 

[Spyderwebb]

My CEL light came on for a while the other day (solid, not blinking), went by the dealership and had them read the code.  It was showing it stored codes U0100, P25A2, U0146 .  These had something to do with the brakes (some sending unit or other). 

 

At my service visit yesterday they performed TSB 20NA155, which I understand was a reprogramming of the computer.  They advised that fixed the issue?

 

The Service Advisor told me that if the CEL light was on but not blinking it's ok to continue to drive the vehicle until you can schedule maintenance.  However if it is blinking then you should get it in right away!

Edited October 7, 2020 by Spyderwebb

[1997SierraSLT]

Get used to it.  If a P0300 code, it is infamous for GM owners since the 1980's as they still haven't figured out how to manufacture a reliable fuel injection system.

 

Might as well purchase an OBD-II scan tool because you're going to be using it frequently owning a GM vehicle.

[Amy Swayngim]

I'm having the same problem on my 2021 5.3, but no codes have been thrown. Onstar, dealership and app shows nothing. Any recommendations as to what it could be?