PID 4Dmin
Time run with MIL on
How many minutes the engine has run with the Check Engine lamp on. The same as PID 21 but in time: distance answers «how far», minutes answer «how long». Together they separate a fault that shows up once a trip from one that is lit all the time. Many minutes with little distance means the car idles a lot — look for the fault at idle.
What is normal
Zero on a healthy car. Together with the distance it shows how long the fault was ignored.
These figures hold for most cars, but the maker has the last word: some engines run hotter or idle higher by design.
Step by stepThe code came back after a reset — what it means
How it feels behind the wheel
The same fault shows itself in different ways. Each sign below says what to look at in the live data.
Check engine came on after refuellingYou filled up, drove a few kilometres, and the light came on. The car drives exactly as before.Check engine came on after a wash or heavy rainYou washed the car or drove through a downpour — and the light came on. It often clears itself in a day or two.
How to see it
In CarScan: the Live data tab, «Start polling». The app asks the car several times per second, draws a graph and remembers the highest and lowest value of the trip.