driving on a cel

[jefla]

I'e a 2000 w/ 40K miles that starts, runs and does everything else as it should. No unusual temps, oil etc. The cel came on yesterday and I'm planning on a 4 hour drive tomorrow. I can't read codes and don't have time to pull them before tomorrow AM, when I leave.

Shold I take it?

[Highlander]

I'e a 2000 w/ 40K miles that starts, runs and does everything else as it should. No unusual temps, oil etc. The cel came on yesterday and I'm planning on a 4 hour drive tomorrow. I can't read codes and don't have time to pull them before tomorrow AM, when I leave.

Shold I take it?

Unless the CEL is flashing, you'll be fine. Did you fill up with gas recently? If the gas cap is not tight, that will throw a code. If the problem is minor, the light may go out by itself after a few start/stop cycles.

Graeme

Edited November 13, 2005 by Highlander

[kwinhouston]

Same thing happened to me on the weekend. Last week, CEL came on just before I filled it up. CEL went out after another 20 miles so I thought no problem. Came back on during a long drive saturday (300 miles), and I got nervous. It stayed on until yesterday when I filled the tank, it went out. Weird.

If it comes on this week again, I am going to have my mechanic take a look.

I have just had the MAF replaced, so the other things I thought it might be is the O2 sensors.

[Loren]

This is not unusual at all. The way the OBD II computer works it can detect a problem and store it as a "pending fault". It continues to check and monitor conditions and if the conditions that cause the fault are corrected then the CEL is never turned on. Likewise, if a fault has turned on the CEL and that condition has been corrected it will turn the CEL off itself after a certain number of prescribed conditions have been met (drive cycles).

For the same reasons if you have an O2 sensor failure, and you then replace the O2 sensor. Then you turn the CEL off with a scan tool and go to get your car smog checked it will fail - because the drive cycle test in the DME has not been met. Sometimes for certain faults this can take a couple of weeks of starting stopping and driving the car without the same fault happening. I think you can thank the EPA for that one - it keeps people from cheating on their smog tests.

[jefla]

An update on my illuminated cel. Car always ran fine while cel was on and cel never went to flash mode. After 10 or 20 "cycles" (start, drive, shut off) the light stopped coming on.