Questions about drive cycle?

Prior to beginning the drive cycle ensure your Sonata has at least 1/4 to 3/4 tank of gas. Where would the needle be on the gauge for either of these? Anywhere within the three middle lines?

STEP 2: (Steady State Driving - Part 1)
• Accelerate within 15 seconds to 50-55 mph (using 1/4 to 3/4 throttle) and keep this speed steady for 2 to 3 minutes.

What is 1/4 to 3/4 throttle? How would I measure that?

• Decelerate to 0 mph without braking.

• Idle engine then idle in Drive for 1 to 2 minutes.

I decelerate to 0 mph but I’m already in drive. It says idle engine THEN idle in drive.

They’re not trying to trick you. 3/4 and 1/4 are fractions, and your fuel gauge is divided into 4 sections by the dashes…

I suspect without reading all the context that you are to decelerate to 0mph in neutral, as decelerating to 0mph in drive, at least without going up a fairly significant hill, would be impossible without braking.

Yes to the first question. Push the gas pedal about half way down for the acceleration part of the cycle. After cruising between 50 to 55 mph, take your foot off the gas pedal and coast to a stop. Since it is still drive, you will probably continue to creep forward. Continue this for 1 to 2 minutes and then put your foot on the brake to stop the car. The cycle should be completed. If it didn’t work, try again.

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normally, monitors would set duiring the normal drive cycle, follwoing proper steps should get it set faster

if you have a bluetooth or wifi OBD2 adapter, try getting a free version of

it shows “monitors” mode, which shows what is set ready and what is not

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So I started the car from sitting all night for a few minutes then drove to the highway (3 minutes) pulled to the shoulder (twice) then went from 0 to 50-55 under 15 seconds for about 3 minutes then the second time close to 20 minutes. Each time I pulled to the shoulder and let my foot off the gas until it coasted at around 20mph then put it in neutral (without barking) and it went to zero. Then I put it in drive (with brake) for two minutes. Then put it in park and shut off engine on the shoulder.

It is hard to determine 1/4 to 3/4 on the peddle. But would seem it is somewhere in the middle. You cant keep a steady pressure on the peddle because you just go faster.

Got home after 2 hours of drivng and connected the OBD 2 and no codes since I cleared them yesterday. IM Readiness shows only evap not ready in Since DTCs Cleared menu and all the 02 sensors, cat and evap show not ready in the This Drive Cycle menu.

I take it I did not complete a drive cycle?

I have this one

It has the readiness monitors. Though Im still trying to learn all the functions and meanings/readings.

I would like one of the bluetooth ones as I read they can send or store the data or reports to your phone, which would be nice.


Those instructions are indeed a little confusing. What I’d do is go to the dealership and ask them to explain. Absent that, fill the tank to the half full mark, then drive to the freeway on ramp and accelerate to 53 mph within 15 seconds by pressing on the pedal half way. Assuming that’s even possible. I expect what they mean is to accelerate normally, not push the pedal all the way to the floor, as that may put the computer in a special maximum acceleration mode. For the deceleration phase I’d just take my foot off the pedal and allow the car to slow down (providing such a thing is safe, don’t stop on the side of the freeway, that definitely isn’t safe), then when you are going very slow as you are going very slow shift to neutral and put your foot on the brake and let it idle in neutral for 2 minutes. The put your foot on the brake, put the trans in D, and let it idle that way for 2 minutes.

Sometime for evap system readiness, the gas tank has to cross a transition, either across the 1/4 full or the 3/4 full mark. That always happens in norming driving when you fill the tank, then fill up again when it is near empty.

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It seems that one or more drive cycles have occurred to completed each monitor except the evaporative emissions monitor. I normally perform a drive cycle after repair and clearing a fault on a customer’s vehicle, it usually takes 10 minutes. Drive with normal acceleration, keep a steady throttle and avoid periods of engine idle.

A natural vacuum leak detection monitor is an over-night test, you can’t drive though it.

An office boy will tell you to drive the vehicle for 75 miles, they don’t get paid to assist the general public.

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I did the drive cycle the next day also, that time I used Cruise Control. Then drove it for the week normally and the monitors were all ready and I passed the emissions.


Good for you. From the frequent posts we get here on that topic, those emissions drives cycles can be very perplexing.

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I worried about the drive cycle on my 2009 Mexican Sienna, so when I put in a new battery, I clamped the 12 volt charger on the cables and did not lose the memory.

But, last week I knew I was going to be driving to Cordoba in Vera Cruz on the high speed tollway. So, on purpose I disconnected the battery cable for a while. I checked the monitors just before I got to Cordoba and they were all ready.

But, that particular 100 mile trip, which takes 3.5 hours going east, and 4.5 hours coming back**, involves a lot of different speeds, and only on the high speed tollway can one go the speeds needed for a drive cycle.

Speed limits on secondary roads here are usually near 40 mph.

**The reason the return trip takes an hour longer is because the east bound lanes are not adjacent in much of the trip to the west bound lanes. I think they are at times miles apart, much like Route 66 in Missouri back in the 60’s. the reason is to have the four lanes close together would take at least twice as much blasting on the mountains, as having each one in its own place.

Yet, the distance west bound is only five miles longer.