Smog/Drive Cycle Information
 

Hi, having problems getting monitors to reset in order to Smog and was told there is a specific driving sequence to do that. I searched "driving sequence" here but did not see anything, where do I find that driving sequence required to reset monitors?

Search for "Volvo drive cycle"

Matthews Volvo site has a good write up - https://www.matthewsvolvosite.com/em...for-readiness/

Thank you! I see there are more than one drive cycles; going to try this one tomorrow:

1. Start the engine and accelerate to approximately 1500-2000 rpm.
2. Drive for 6 minutes at 1500-2000 rpm.
3. Stop the vehicle and remain at idle in drive for 70 seconds.
4. Accelerate to at least 45mph and drive for 5 minutes at 1800-2200 rpm.
5. Stop the vehicle and remain at idle in drive for 60 seconds.
6. Accelerate to at least 45 mph and drive for 4 minutes at 1800-2200 rpm.
7. Stop the vehicle and remain at idle in drive for 60 seconds.
8. Park the vehicle and turn off the engine.

It works best if you are on relatively flat ground and use mild throttle application. If you have to stop (for a traffic light or such) during the minutes listed - once you get back up to speed (rpm) the test continues. If you have a compatible scan tool you can watch as you are driving the monitors complete and clear. The o2 sensor operation, cat efficiency and evap system are tested last. The o2 heaters are tested on every start if cold. Allegedly on some cars you have to do that twice - and there is mention of starting the car and warming it up to between 80-120degress. then shut off and restart. Perhaps in cold climates that is needed. Good luck, my service writer spent a lot of time driving customers cars to complete drive cycles - I would just do one every once in a while.

Thanks hoonk, a new piece of info: that if you have to stop, once back up to speed test continues. Many tries at test, and you run into a car going too slow, and have to break speed/cycle, and assuming need to start over. And another piece too, the start car/warm up/shut off before test is something I had not heard.

Did read multiple comments with mechanics saying that just enough normal driving the monitors will set.

Also, with patience over the phone, was able to get through to a senior officer in the Bureau of Automotive Repair (BAR) in California, and they are going to send notice to Sacramento to send me a temp registration so I can continue driving to reset.

That is true for most cars and later Volvos - but some Volvos in the 96-2000 year range won't easily complete a drive cycle. People who don't drive a minimum of 17 minutes under the right conditions will never complete a cycle. That's about how long it takes to get to the evap portion. If the typical traffic in your area is too fast (on the freeway) or too slow or terrain is too hilly a cycle won't complete. The area we would use is a flat interstate access road that went between several exits and you could loop back the other direction without waiting at a traffic light. 45 mph speed limit, not much traffic, and places to pull over and idle.

I've seen drive cycle writeups that say to turn the compressor off also -

Thank you. If I can't get it done here, might have to drive out to desert for long flat stretches.

Throttle needs opened gently and not floored, and I believe the fuel tank has to be between 20 and 80% full to test the evap system. .

The official Volvo schematic says accelerate to 45-50 in under twenty seconds, but I had luck with the alternate cycle based on maintaining rpms; knocked down to the EVAP alone, and when I got to the Smog Station, the CAT had come back on. So many takes on how to do it, or that with enough varied driving they will set. Truly defeating situation. I'm attempting to get the BAR to include 99s to the 98 or older criteria.