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2016 5.3l Sierra Knock Sensor

Re: 2016 5.3l Sierra Knock Sensor

Postby Root2812 [OP] » Jul 29 2020, 8:20pm

I knew you were just pointing out there could an engine issue causing the light too. I’m hoping the dealer will solve it no matter what the cause is. I just need the truck back. I’ll ask the dealership tech to look for carbon but I would guess he probably would anyway. Maybe they’ll do that chemical cleaning too.

How does disabling the AFM change things? How would I do that? I don’t really know how it works. I know I have the Displacement on Demand where it goes into 4cyl mode. If my camper isn’t hooked up I want fuel economy more than fun power so I want to keep the DOD.

Yes I got a good deal on the truck but for a reason. It was on a dealer lot when someone took it for a November test drive. They spun out and put both sides into guard rails. I bought it at auction 2 years ago for $14k and then repaired it enough to drive. It took a windshield, two fenders, two headlights, a mirror, a tail light, a rim, and an alignment and I’ve been driving it since. It was all cosmetic stuff after that and all the airbags were good. Still a good deal for a 12k mile crew cab with leather. I already picked up a replacement box and bumpers so if I ever get around to bodyworking the doors I’ll paint it and it won’t look trashy on the outside. After I fully fix the body up I’ll still be in it under $25k which is a deal over the $42k NADA it had at the time.
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Re: 2016 5.3l Sierra Knock Sensor

Postby EaOutlaw1969 » Jul 29 2020, 9:19pm

Well if you want to keep the AFM-DOD active be more proactive with oil changes do not wait for the computer to tell you to change it.
Disabling it just requires a device that plugs into the diagnostic port under the dash once plugged in the truck can no longer go into 4 cylinder mode making it less likely for a lifter to get stuck and or damaging the camshaft and causing other problems that could lead to needing a new engine.
Disabling the AFM makes it less likely to break down but not impossible.
Just search the internet and this forum about AFM or DOD and you will learn all you care to about the issues with this system. BTW the device that plugs in can simply be unplugged and your AFM system goes back to work if you so choose. since you are talking wanting 200000 miles or more out the truck you should really learn more about what your driving so you can take a proactive approach to preserving it.
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