Check engine light blinking?

[Changfriedrice]

Hey all! First time to this website as well as a first-time owner Mustang. I just bought my brand new 2019 Mustang GT back about a month ago. Yesterday when I was on the merge ramp for the highway, I noticed the check engine light was blinking during my acceleration and after (~20 seconds). It went away immediately after. I've heard that this is a sign of a misfire and that it could possibly be several issues like the spark plugs, catalytic converter, etc., but it hasn't shown up since, even after I've tried replicating the situation (light turned on ~4500rpm). There was no shaking or power loss that I noticeably felt. The extent of my knowledge stops here. Was it a ghost misfire, perhaps? Should I get this checked out or read with an OBDII scanner? The car is ~1500 miles. Thanks for whoever helps!

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[Rjames18]

Had this happen on my first 2018. Never figured out why it kept doing that.
Eventually it left a code, said multiple misfires.
Just had it cleared and everything was good after that.

 

[gmupatriot]

I had my 2018 GT throw P0300 CEL (Misfire) (no other codes) after a cold start on a 5F morning. I had the code read at Auto Zone and didnt erase it because the car drove fine. After 200 miles over 3 days, the CEL went away. The car drove fine then and still drives fine. Unless you notice driveability issues, I wouldnt worry much.

 

[philk]

Happened to me too at 6500 miles. Brand new 2022 Mustang GT Premium. But haven't seen it again since.

 

[Cobra Jet]

Hey all! First time to this website as well as a first-time owner Mustang. I just bought my brand new 2019 Mustang GT back about a month ago. Yesterday when I was on the merge ramp for the highway, I noticed the check engine light was blinking during my acceleration and after (~20 seconds). It went away immediately after. I've heard that this is a sign of a misfire and that it could possibly be several issues like the spark plugs, catalytic converter, etc., but it hasn't shown up since, even after I've tried replicating the situation (light turned on ~4500rpm). There was no shaking or power loss that I noticeably felt. The extent of my knowledge stops here. Was it a ghost misfire, perhaps? Should I get this checked out or read with an OBDII scanner? The car is ~1500 miles. Thanks for whoever helps!

Welcome to the site and to S550 Mustang ownership!

I posted this below info in another "misfire" thread, so take some time to look through it.

This thread may give you some enlightenment to Ford's misfire strategies:
https://www.mustang6g.com/forums/threads/good-tech-article-on-ford’s-misfire-strategy.108076/

Also here is a pdf snip from the Ford Shop manual. which is "Coyote" specific. I'm including it because it gives a bigger picture of how to diagnose misfire events from the generic to the actual cylinder event codes:.
https://www.mustang6g.com/forums/attachments/hd-misfire-detection-pdf.538665/

You could have a faulty crank sensor OR one with loose wire contacts in the actual connector, which will also cause sporadic "random misfire" events. Other M6G members have found that the P0300 was related to a faulty crank sensor. This could be your issue too, so review each thread carefully because each owner came across it in a different manner.

Check this thread:
https://www.mustang6g.com/forums/threads/misfire-at-high-rpm.174380/#post-3531453

AND this one:
https://www.mustang6g.com/forums/th...e-sensor-tone-ring.156234/page-2#post-3197692

 

[Jackson1320]

I would not worry about it unless it continues to happen

 

[Black19GT]

happened to my 2019 when it was close to new as well. Dealer checked codes and it came up as a misfire on two cylinders. Remedy was that they replaced spark plugs in those two cylinders and have never seen it again.

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