Alaska SS

So, I got my car back after being in the shop for 2 months. Now I need to get the car smogged but I can't get the drive cycles to reset. On my OBD2 scanner it says Cats, Fuel and Evap are not complete. On the shop scanner it show just Fuel and Evap. I've done the OBD2 drive cycles multiple times, I have over 280 miles on the car since getting it back. According to my scanner not one of the incomplete tests has completed. Fuel is between 3/4 and 1/4. I've tried everything. There are no hard codes on the car (DTC). Any ideas, I'm desperate. Car is a 2015 Z06 with Headers, high flow cats and a tune.

RicK T

Nevada will pass a car with "one" system not set. Any chance the high flow cats aren't doing the job?

Although I've read here that the C7 system reset is different than the C6 was, when I had to replace the battery in my C6 the same month as the smog test was due, I went to Jiffy Smog, they tested, it failed on 2 systems, they told me to drive it "a little" and do multiple ignition off / on cycles. I did that, basically just started the car in the driveway, ran it and shut it off 'till cool. Did about 5 or 6 restarts over 2 days and took it for a retest. It passed with only 1 system not set yet. So I don't think you have to take a driving trip to put miles on, just several ignition cycles allowing to warm up each time. I'm sure someone will chime in with definitive C7 cycling info so be patient but might try this anyway.

TXSteveF

I had a similar problem and even though it doesn’t fit you situation I’ll throw it out there in case it’s at all helpful. I couldn’t pass and had about 9K miles on mine. I always had the Range in and would only take it out when I dropped it off for the test. Then I unplugged it for a week and drove in manual and I finally passed. I saw you had a tune so maybe it’s doing something but I really have no idea. Just wanted to share my issue.

Alaska SS

It's killing me. I've had it back since Friday of last week. I've driven it to and from work every day on top of the drive cycle reset specific trips I've done and nothing. I would understand if it was throwing a code but there is nothing. I'm at a total loss.

TXSteveF

It took me three tries to pass. I only assume it was the Range. I was really frustrated. Our state is controlled by each county and the one next to mine doesn’t require a smog test so I almost drove to a station there. Someone will chime in with something helpful, they usually do.

Good luck.

rmorin1249

I have the same issue. No problem passing emissions the first time, was not using a Range. Now I have 20k miles on the car, been using a Range and was told I need to drive it at least 100 miles and come back. Do I need to unplug the Range and drive it 100 miles?

Alaska SS

Okay, dumb question...what is a Range?

rmorin1249

Device that prevents V4 mode.

Alaska SS

Ah, okay. I don't have one.

TXSteveF

I did. Unplugged it and drove all week in manual and when I took it back I passed. From what I understand it has more to do with the cycle times, which is letting the car cool completely down then heating back up. Go through maybe three cycles and I think you should be OK.

jdk541

I am having the exact same issue. I was thinking of starting a post on it. 2014 Z51, M7, completely stock. I have been through emissions 3 times in the last week and it won’t test. Had it at the dealership today and the technician reset the ECM. Told me to drive it a lot the next few days and they will hook up the tester to see what it shows.

The printout from the emissions testing site says my O2 sensors are not registered, but the dealership checked them and they are fine.

I’ll report back as I solve this mystery. Car is running great and everything works as it should. Very frustrating though.

RonC7

I had a similar issue with my Trailblazer after a dead battery. I plugged a bluetooth modem into the ODBCII port and just drove the car normally for a few days - errands, short trips, lots of ignition cycles. All showed ready in a few days and it passed emissions.

Ron

Kracka

My guess is the problem is in the tune; the codes are likely disabled. Talk to your tuner.

snomuncher

When the emissions systems monitors are "not ready" on an emissions test report, it may take more than just driving the car before they reset. For years GM cars and trucks have had OBD2 drive cycles that vary based on year and model. You can find generic OBD2 drive cycles on the internet that sometimes work for older vehicles but the ones from the mid-2000s forward on cars like Corvette are more complex. I'm in the middle of the same issue after pulling my C7 out of storage. Even using a tender to prevent the battery from dying was not sufficient (a dead or disconnected battery in storage can cause the same issue) so I'm using the specific drive cycle specified in the service manual. Technically it's called the Inspection/Maintenance (I/M) System Set Procedure. Too lengthy to list here- two full pages of the manual- it's in the Engine Controls section (on pages 9-394 and 9-395 for 2015 models). It involves driving at certain speeds for periods of time, running at idle for a period of time, running at different throttle positions with the brake on or off, not disturbing the vehicle for a period of time after turning it off and waiting a period of time before repeating all of this if the monitors are still not ready. I usually have a partner with me to read the steps as I drive the cycle. The manual also states that this drive cycle may need to be repeated up to 6-12 times. A couple of basic points about it are that it should be run with all accessories off and that it might require waiting up to 17 hours between cycles for the EVAP systems monitors to reset. All of this assumes no trouble codes are involved.

rmorin1249

Why is it so complicated? Is this unique to GM cars? I have never had this issue with other brands I have owned, What effect, if any, does a Range have on this process? I use my car on a regular basis and it was not in storage this past winter. It isn't driven every day but it is driven on a regular basis but with a Range plugged in. Should I remove the Range and drive it? For how long and how many times do I need to start it and then turn it off? This is very confusing and frustrating. Sorry for all the questions.

dmaxx3500

just more GOV bull crap

jdk541

In Arizona when the car get rejected for throwing a "Not Ready" code, they hand you a piece of paper and it tells you to do the following to "Become Ready".

1. Start with a vehicle where the engine has cooled all the way down over night.
2. Fuel level between 1/4 & 3/4 full
3. Drive between 20 & 30 MPH for 22 minutes, allowing speed to vary.
4. Stop and idle for 40 seconds, gradually accelerate to 55 MPH.
5. Maintain 55 MPH for 4 minutes using steady throttle input.
6. Stop and idle for 30 seconds, then accelerate to 30 MPH.
7. Maintain 30 MPH for 12 minutes.
8. Repeat steps 5 & 6 four times

I just completed this about 30 minutes ago, which isn't easy in the Phoenix metro area even on a Sunday morning. I'm not sure how they expect you to actually do this without breaking the law or obstructing traffic.

Anyway, my car is "locked-out" from re-testing until next Saturday. The team at Freeway Chevrolet who reset my ECM yesterday told me to bring the car back mid-week and they will hook it up again to see how it looks. Hopefully for me the 4th time will be the charm.

TXSteveF

If you have the time, and patience, I’d try to pass before you drive it without the Range. If you fail drive for a week or so and take it back. I have no idea if the Range is the problem and you can help figure that out. It did appear to be my issue. Not a big deal just inconvenient to take it back.

rmorin1249

Damn, I agree. Not sure where I will find roads around me that will allow me to drive at these speeds. I guess I can find a parking lot for the slow part and then get on the interstate and **** off a lot of people driving 55. This is BS!

rmorin1249

Success! Disconnected my Range. Drove around for about a half hour at various speeds mostly in Manual, about 25 miles. Back to the Emissions place, passed with no problems.