PID 21km
Distance with MIL on
Distance driven with the Check Engine lamp on. It only grows while the lamp is lit, so it shows how far the car has already been driven with a fault. PID 4D counts the same thing in minutes. Distance matters more when the fault shows itself at speed; time matters when it appears at idle and in traffic. A large figure with an empty code list means the codes were cleared recently.
What is normal
Zero on a healthy car. A large number with an empty code list means the codes were cleared recently.
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.