Engine light question

I have a 2001 Ford F-150 v6 2wd. A few weeks ago, the check engine light turned on so I drove to the nearest autozone to hook up their computer and see what the error code was. The technician gave me the code (I don’t remember it off the top of my head but it wasn’t something imminent). Before leaving, I asked him if he could clear the light, figuring that if it didn’t come back on after 50 miles, that it might have just been a fluke with one of the truck’s sensors. Later that day, I realized that when I started the truck, the check engine light was no longer turning on momentarily the way that all the dashboard lights do to tell you that they’re working.

I went back to a different autozone (one closer to my house) and explained the situation. They checked the computer for codes again and found none and said that the light must not be turning on because the bulb is burned out. I find this to be a striking coincidence that the bulb should happen to blow out exactly when the technician used his computer to clear the light. Is it possible that he did something with his computer that permanently disabled the check engine light? It’s been a few weeks and I’ve since bought an inexpensive bluetooth code reader of my own, hooked it up, and found that there is still no active code. Is it possible that the code has returned or will return, but that I won’t have a way to know because something he did supressed not just the light but my car’s code reporting mechanism?

For now, the truck drives fine, but I’m afraid to travel long distances when there might be a problem I don’t know about.

I’ve searched the web but could not find answers to these specific questions.

Thank you for your help!


Rather than worry about it, I would just fix the light and move on. Anything amiss will present itself in due course.

The truck is 12 years old. I use a scan tool every day, and there is no direct connection between it and the CEL. The ECM turns the light on and off, not the scan tool. The scan tool can erase the codes, and the ECM turns off the light. I think the light bulb just had enough.

I have a 2000 Explorer, and had to recently replace the instrument back lights and the airbag warning light. I suspect I had two or three backlights go out, but the airbag light cinched it. With the airbag light out, the truck would beep at me everytime I started it up. Since I was replacing that bulb, I changed out all the backlights whether or not they were blown. Just didn’t want to have to do it again.

@dvi2020 fix that light now, or you WILL fail the next smog inspection

In the event that the bulb is still good then the possibility exists that the ECM could be going a bit stupid by not providing a ground for the bulb (currently) or inadvertently providing one several weeks ago.

At this point, I would suggest that you disconnect the negative battery cable for a few minutes. This should reset everything. You will have to reset your clock and radio presets.

Thank you for the reassurance Bustedknuckles and the advice ok4450, db4690, and keith. I will start by disconnecting the battery and take it from there. Thank you

Make sure you have your radio code handy before you disconnect the battery, the radio may not work afterward.