failed smog - california

**timaishu** · 08-06-2011, 03:27 PM

It passed the emissions and visual test. But I failed the functional check. This is what the print out says, "This vehicle failed the MIL/Check Engine Light due to failure to successfully complete all OBD self tests."

The guy told me the OBD II monitors for the Evap and O2sensor are "Not Ready".

He told me I need to do some driving to reset it or something? I did some searching online and people mentioned drive cycles and such.

I have been unplugging my battery lately swapping radios and I had my car worked on a few days ago and they maybe reset something? Is this a re-learn procedure type deal?

I have an 05 Nissan Altima 3.5SE with 89k miles.

Can anyone shed some light on this for me?

**Mobile detail** · 08-06-2011, 03:46 PM

Unplugging your battery resets your monitors. You need to allow the computer to go through it's drive cycles and NOT disconnect your battery until your done with smog.depending in the vehicle they can be a pain to reset. you will have to drive it for a bit and get up to freeway speed in order to reset. If time is an issue, you can have the smog repair shop put it on thier dyno machine and run through the cycles for you. What kind if vehicle is it?

**timaishu** · 08-06-2011, 03:51 PM

05 Nissan Altima 3.5SE.

Second line from the bottom.

**diablojota** · 08-06-2011, 04:02 PM

I had the same issue with my Vette. I left the battery disconnected for some time because it kept losing charge, so when I went for the inspection it failed. I didn't even think about the computer clearing its memory when unplugged. You'll have to just drive it around a bit. Many cars you can simply go and drive them for about 20-25 miles on the highway until they reset. That's what I did. Took a nice, long drive. Afterward all was good.

**SpoiledMan** · 08-06-2011, 05:18 PM

My understanding was 50 miles of driving. Speed doesn't matter. I got on an empty freeway and drove from one end to the other and went back. Test passed.

**Tyrod** · 08-06-2011, 05:33 PM

Actually, just driving won't solve all the problems. Especially on newer cars. What a lot of tests are looking for are start stop cyles. Certain tests, will only run the test cycle once per ignition on/engine running period and may need several cycles to complete the test. Worse, if a test fails, it may take up to a hundred cycles to reset.

For example. Suppose, for some unknown reason cylinder #1 has a misfire. Maybe a grain of sand shorted out the spark plug or a near microscopic bit of water entered that cylinder. But, it only happened once. Now everything is ok. The computer won't give you SES or MIL light or whatever you want to call it for just one misfire. But, the computer remembers the code and stores it in a location called Pending Codes. If, within a preset number of cycles the computer sees another misfire in cyclinder 1 it will then trigger the dash light. The cycles are all different for all different makes of cars, years and sometimes between models for each specific test.

So driving the car is good advice as long as you stop a few times and turn the car off.

**Twister** · 08-06-2011, 05:38 PM

I get that problem with my TA every now and then. Just do some driving or look online for the peramitors for the test.

**SpoiledMan** · 08-06-2011, 05:57 PM

You don't need to stop and restart. If there is a malfunction it will turn the MIL on again. Start, do 59 miles and go for the test. If the light isn't on, you'll pass.

**timaishu** · 08-06-2011, 06:53 PM

So do you think this was related to me unplugging my batter then? I just went on a 56 mile drive.

Gonna maybe do some short errand trips tomorrow and try again monday.

Hope I pass.