Randomly Occurring Flashing Check Engine Light

[Anastasios Tziolis]

I have a 2016 Chevy Tahoe 105,000 miles. Twice last week a few days apart my check engine light began flashing about 15-20 minutes into my commute and turned off within about 1-2 minutes both times. My spark plugs were replaced at 97,576 miles last October at the dealership and the coils, boots, etc, were inspected . I’ve been told that putting a tank of high quality supreme grade gas could help the problem. Has anyone else had this issue?

Edited March 27, 2021 by Anastasios Tziolis

[cs15dah]

Flashing may mean there’s a misfire going on. Check for pending DTCs. Does the flashing maintenance indicator light happen when you’re accelerating or cruising?
 

Quality fuel is always good and always should be used. But 87 octane is all you need. “Supreme” does nothing for you. That word is simply a marketing scheme. These trucks do not require high octane. Folks have mixed outcomes with using a fuel injection/system cleaner. The likely hood that this’ll help your problem is awfully low, but may be worth a shot. You can buy fuel injector/system cleaner locally, or just use high quality detergent fuels.  

[reardiff]

On 3/27/2021 at 3:45 AM, cs15dah said:

Flashing may mean there’s a misfire going on. Check for pending DTCs. Does the flashing maintenance indicator light happen when you’re accelerating or cruising?
 

Quality fuel is always good and always should be used. But 87 octane is all you need. “Supreme” does nothing for you. That word is simply a marketing scheme. These trucks do not require high octane. Folks have mixed outcomes with using a fuel injection/system cleaner. The likely hood that this’ll help your problem is awfully low, but may be worth a shot. You can buy fuel injector/system cleaner locally, or just use high quality detergent fuels.  

 

Unless you have the 6.2 which does recommend premium fuel. 

 

[nfisherman]

It's hard to say what's wrong without knowing which code was generated. I had a similar problem with my 2015 Sierra. I don't recall the specific code, but it was related to a faulty catalytic converter. I had been using 87 octane gas from a cheap gas station near my office almost exclusively. I went to a station that advertised top tier gas. I filled up with a tank of 93 octane. It worked for me. The light went off after about 200 miles. You might want to give that a try. It won't hurt anything.