Quote:
Originally Posted by amir_gh
I will take a look, but there is no check engine light. Is there a drive cycle requirement to clear permanent codes? Is the following true?
The time to complete 15 warm-up cycles and drive 200 miles is reasonable for vehicles to complete the self-diagnostic tests. In fact, most vehicles will complete the self-diagnostic tests well before this maximum limit is reached. The 15/200 limit is being established to prevent undue inconvenience to motorists who are trying to comply with the Smog Check Program requirements but are having trouble getting specific monitors to run to completion and ready for testing.
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The Check Engine Light function is just a dumb catch all notifier. It means, “hey, there’s a sensor that’s reporting a problem, go tend to it.” Or “you’ve driven X thousand miles, better get some service”. If you clear it, it goes away as if to say “OK My job is done.” But the original problem is stored as the specific DTC in memory. Just because the DTC is still in memory it won’t retrigger the Check Engine light On again.
The MAF is part of the emission control loop so it probably does need a drive cycle to clear it. But you need to address the problem that caused it to be set in the first place. Check that connector. Make sure the air filter is OK and the lid is closed properly. Maybe you do have a dirty MAF that needs cleaning. Then drive. Sometimes hitting the specific sequences in the drive cycle is tricky and it does take a long time and many miles to complete it.
If you’re in a hurry to get ready for a smog test you may have to research the drive cycle parameter profiles and follow them exactly. I did this for my 3rd Gen.
