PID 4Emin
Time since codes cleared
Minutes the engine has run since the codes were cleared. The same as PID 31 but in time. The pair is useful precisely together: the odometer is easy to reset from the cluster, while minutes since the clear live in the engine unit and are harder to fake. A small figure next to a clean code list is a reason to drive and check again.
What is normal
Useful when buying: a small number means the memory was wiped just now.
These figures hold for most cars, but the maker has the last word: some engines run hotter or idle higher by design.
Step by stepHow to get ready for an emissions test in a week
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.