computer codes vs. check engine light

The tech's comments this morning cauesd me to wonder. He said he read a condition codes on my engine. However, the "Check Engine" light was not on, and hasn't come on in many days. About two, two-and-a-half, weeks ago the light came on intermittently, after the first test by a dealer. I'm wondering if my light is dysfunctional. The bulb isn't dead since it lights up when the key is first turned on.

My question is, does the check engine light always come on when the computer stores an error code?

-D

Reply to
Derrick 'dman' Hudson
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Nope

Reply to
Bob

No the light does not always come on when a code is stored. Codes are also stored for a varying length of time (usually based on key cycles) even after they go out. For example, disconnecting the batteries in my F250 will cause a code to be stored that will not set the SES light.

Reply to
bomar

Interesting... Yesterday, after I'd re-charged my K&N filter, I got a flashing SES lamp for about 10 seconds while driving up a moderately steep hill. Took the truck over to AutoZone to look at the OBDC... nothing. System passed with no codes. I haven't done anything to intentionally re-set the computer. The truck seems to miss while idling in drive, and sometimes under moderate load (hill)/accelleration. Air filter is taken care of. Fuel filter next?

Happy New Year, Scott

2001 SuperCrew 5.4L 45,xxx miles
Reply to
scott

On Fri, 26 Dec 2003 14:40:11 -0600, scott rearranged some electrons to form:

Are you sure you hooked everything back up after you messed with the filter?

Reply to
David M

Beware that the cheap code readers at Autozone and their ilk will not pull every code....

Reply to
bomar

plus, on a 01, you have both 'OEM' and 'OBD-2' codes, plus 'slow', 'fast', and 'pending' codes

Reply to
Gary Glaenzer

Ok. Thanks.

-D

Reply to
Derrick 'dman' Hudson

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