Whether you’re a mechanic or just interested in knowing what’s going on under your vehicle’s hood, a basic drive cycle is critical to understanding repairs and emissions testing.
What is a driving cycle?
Without going too far into the weeds, a basic drive cycle will ultimately help you or your mechanic know how successful recent repairs are and what — if anything — needs to be reassessed.
How do you do a drive cycle?
Performing a drive cycle is simple, but takes a little preparation and time to complete. It can also vary among vehicle manufacturers, make, model and year, so be sure to check your owner's manual for additional information and specifics.
These, however, are 10 general guidelines for performing a basic drive cycle:
- Clear all OBD II error codes from your OBD II health monitor. The drive cycle cannot begin until this step is completed.
- Ensure your fuel tank is somewhere between 30% and 70% full.
- Check the quality of your battery and alternator. Jump starting your vehicle is not an option if you want to perform a true drive cycle.
- Let your vehicle rest for eight hours. Do not put the key in the ignition or unlock the car doors during this time.
- Start your car, put it in park or neutral and let it idle for two or three minutes.
- Turn on your headlights, heater and defrosters for at least two minutes.
- Drive to where you can safely reach 25 mph. Make a slow, full stop at each stop sign or stoplight. Increase your speed slowly and steadily to 35 mph and then 45 mph.
- Find a freeway ramp and accelerate normally to merge with other drivers. Stay in the slowest lane and steadily increase your speed to 55 mph or 60 mph. Activate cruise control and maintain speed for at least five miles.
- Find a decently sized exit ramp and cruise to the end of it, allowing your vehicle to naturally decline in speed. You may use your brake at the end of the ramp.
- Return home or to your mechanic repeating step number seven. Upon arrival, put your vehicle into park and let it idle for one to two minutes.
Perform An OBD II Scan
You or your mechanic can now perform an OBD II scan and determine if your vehicle is repaired and ready to pass an emissions test.
Keep in mind that a basic drive cycle should mimic a typical person's commute. In this instance, your engine's computer will run a series of tests to make sure everything is operating as it should.
How long does it take to complete a drive cycle
Preparation for it will take eight hours but, all in all, a basic drive cycle test should take around 30 minutes to complete, with about 20 minutes of actual driving.
Understanding your vehicle's overall health can help you ensure it drives smooth and lasts long. Keep an eye on your dashboard notifications and perform regular checkups when possible — it'll be worth your time and money in the long run.