Have any of you out there heard of this? I got a new (used/rebuilt) engine place if my car recently, and a previous engine light error code came up for insufficent EGR flow. Mechanic fixed that with a DPFE switch/part. That went away, and recently while I drive betwen 60-70 mph the engine light would blink on and off a few times, or when i went under 60 mph. Long tale small, it was coming up with “misfired cylinders” codes. Mechanic couldn’t know why, he test drove it, and like me, that engine/car runs fantastic, nice and charming, and bounty of horsepower, no hesitations, no rough sounding, nothing. Engine runs fantastic. He place in new ignition coil, new OEM spark plugs, new wires, diagnosed engine, everything he may possibly reflect of, but couldn’t find the reason the engine light would blink, and then go off if I drive under 60mph. Recommended i have some type of “exhaust airflow check” done at some exhaust shop. (they didn’t do that at their shop). No biggie, as I was driving home that night, i passed the auto shop to see if they did it by exchange. Long tale small, they did a complete breakdown of my engine, and like the other mechanic, may possibly not see other misfiring’s that the computer was showing on my engine light. They drove it like I did, and may possibly not find anything. A few hours and a few calls later, they determined it was the software on the computer in my car was from the ancient engine. Mechanic said he’d have to update the software because of the engine I had now.

Now I’m no mechanic, but as an IT geek by day, I understood what he was saying about upgrading the software, and I know cars have “computers” in them, but once he place new software in the computer, lights don’t come on anymore at all, even above 75 mph. He fixed the engine light problem.

I do remember years ago with my previous car, I did have to buy some type of “computer board/part” for my other car, so I know cars have “computers”, but upgrading the software like we do on our home PCs was nothing I ever heard of.

Again, for the mechanically inclined out there, does this sound right? or did he just “rig it” somehow to get rid of the blinking engine light?

i’m not complaining at all, because whatever he did, he fixed it, just wondering if what he told me sound legit
Sorry, 1st part should read that when I went under 60 mph, the blinking engine light WOULD GO AWAY, only blinked when I drove 60-70 mph.

Best answer:

Answer by LeAnne
You didn’t specify the model, but it is common practice to upgrade the software on a Ford whenever there is an upgrade or modification recall or TSB on certain calibrations.
The new program is burned into the computer much the same as a new BIOS force be be installed on a home PC. It basically changes the parameters that are used to set the MIL light and the corresponding fault code(s).

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