How to check car miles with an OBD2 scanner

You can verify if there were any rollbacks on the odometer just by looking at OBD2 live data. There are a lot of different live data values that can tell you either the mileage or at least give you relevant information like working hours. Some control units store their mileage which can be read with the OBD2 scan tool. Some don’t contain the exact mileage number but can provide relevant information.

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In the video above, I used 3 different OBD scanners on a car with a rolled-back odometer. In the video, the car Skoda Rapid is “clocked” from more than 530k kilometers to 360k.

Which OBD2 scanner detects mileage fraud?

You need a scanner that can access all control modules and read data. All Bi-Directional scanners can do that, here are a few examples in the DIY price range:

Scanners for mileage fraud detection: https://amzn.to/3AeQq7e (Amazon)

How to check if the mileage is genuine?

You can find the stored mileage or any data that will help you determine when the engine has run or the car was driven.

Remember that every car is different, and every car does not store the same live data. That’s why knowing multiple ways to determine a car’s mileage from the live data is important.

1. Look for stored mileage in different control units.

Every car brand has its own name for mileage live data. These are the common ones I know.

Vehicle distance driven	Control unit distance driven
Total distance driven	Total mileage
Mileage	Distance
Odometer	Control module distance

Both tools I listed have built-in finders when you enter live data in control units. That way, you dont need to scroll through all of them; try inputting one of these keywords to see if there are any.

If you are in a control unit that should have stored mileage value and can’t find it, it is worth scrolling through live data one by one to make sure that it isn’t called some other way you could find with these keywords.

2. Find engine working hours and average speed

I dont know about all cars, but many VAG cars will show the short-term and long-term average speeds on the dashboard.

Now even the long-term average speed isn’t calculated from the whole car’s life; it is an average of maybe last 1-5k miles. But you can get an idea of the average speed from a sample like this.

And when you find out the working hours of the engine, you can do simple math to verify if the odometer’s mileage is genuine.

Average speed	25 mp/h
Engine working hours	7500

You have to multiply the average speed by the number of working hours to get the estimated mileage of a car.

7500 x 25 = 187 500 miles

This is the estimated car’s mileage, and it shouldn’t have more than that. The dashboard should actually show a 10 – 20% lower value, like 160 000, because this calculation doesn’t take the time engine is running without the vehicle moving into consideration.

If you are at red lights or just parked with the engine running, the operation hours will increase, but the mileage is not changing.

3. Find working hours of OEM radio

This is the slick way of how to check total mileage on car if everything else failed. The multimedia control unit can also store the working hours of the radio. When I run an estimation from the working radio hours, I will consider 75% of these hours.

That is because sometimes you have the radio ON, but the engine is not running. It is not precise, but you can get at least a roughly estimated mileage.

Then again, multiply those hours by the average speed of a vehicle.

Radio working hours	10 000
75% of the working hours	7 500
Average speed	25 mp/h

Different data still get us the same result as the previous example.

7500 x 25 = 187 500 miles

4. Try to find any history logs

Some of the OBD2 software will pull the historical records from god knows where. Here is the data I could find from 3 years back, helping me to understand how much the car was driven and what the mileage was before 3 years.