Ford Focus CEL On, then off?

I was driving my 2004 Ford Focus ZTS on the highway last Sunday and noticed the check engine light come on about halfway through the 200 mile trip. No other lights or warnings came on (oil, temperature, etc.) so I kept driving. I didn’t have time to take it into the shop until Thursday, so I drove it to work (approx 15 miles city driving round trip) for three days.

I noticed on Wednesday night that the check engine had gone off.

What would make it turn itself off after being on for three days? Can I wait to get it checked out until payday (next Wednesday?)

Whatever problem that the ECM saw, has not appeared again in subsequent trips. So the ECM canceled the CEL. The trouble code may still reside in memory. If you want to get a ‘heads up’ on the problem, scan the computer for codes. The code will address the area where the computer is seeing a problem.

Hope that helps.

You could have the computer codes read to see what turned on the light, or you can wait until it comes back on again. As long as it’s off everything is OK.