Won't go into V4 mode

Loco-diablo · October 30, 2019

I ran into an issue this morning. I was on the highway going about 70 mph (flat terrain), the CEL came on for a few seconds (2-3 seconds), then went out. I noticed after that the truck wouldn't go into V4 mode like it always does.. It appeared to be running ok the following 20 miles or so to work, as I didn't notice any noises or power loss..it just would deactivate to V4..The CEL never came back on during the rest of my drive.

We'll see how it behaves on my ride home this afternoon..Do I have a problem? 2017 Chevy 5.3.. 43K miles.

BigBadSierra · October 30, 2019

You will need to get the codes read off and see what it complained about. Most likely a miss fire.

The V4 will disable if your have cylinders reporting a miss fire.

My 2016 did the same thing when I had CEL but it was caused from washing the top end with GDI intake cleaner.

The truck didn't go back to V4 until after I cleared the codes.

I'm not sure if it will reset after a certain amount of time on it's own.

Grumpy Bear · October 30, 2019

"Little known fact"; I've always wanted to say that. A cylinder can misfire up to 15% of the spark cycles before the driver will feel it doing so. 2X on a code read but explains why it could and it seemed to be 'running fine'. Just FYI.

Loco-diablo · October 30, 2019

Ride home was fine.. no CEL, truck was acting normal with V8/V4 modes

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newdude · October 30, 2019

I'd still see what code is set in the ECM. Obviously something turned the light on.

Loco-diablo · October 30, 2019

I'd still see what code is set in the ECM. Obviously something turned the light on.

I’m curious as well.. I’ll try to get the code.

Grumpy Bear · October 30, 2019

Unplugged my MAF once and it upset my ECU setting off the second stage of the oil pump for the entire key cycle. Off and back on.....cleared the code and it never happened again. Ghost in the machine. Static spark? Computers, right?