PID 0Crpm
Engine RPM
Crankshaft speed.
What is normal
At idle most cars sit at 650–900 rpm, steady once warm.
These figures hold for most cars, but the maker has the last word: some engines run hotter or idle higher by design.
Codes about this parameter
We have a detailed piece on thisGeely over OBD-II: what answers and what stays silent
Step by stepHow to find which cylinder is misfiring
Codes behind this reading
If the value is out of range, the unit usually says so with one of these codes.
P0335Crankshaft position sensor circuit malfunctionP0336Crankshaft position sensor circuit range/performance
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.
It stalls while drivingThe engine dies while the car is moving — at speed, in a corner or when lifting off. The steering and brakes go heavy at once.The air conditioning will not come onThe button presses, the light comes on, but there is no cold air. Sometimes the compressor clutch does not click when switched on; sometimes the cold disappears only in heat or in traffic.Will not start in ParkIn P the starter is silent, but in N the car starts. Or the other way round. Sometimes every gear letter lights up at once; sometimes cruise control will not engage.The revs are capped and the car will not accelerateThe pedal is flat to the floor but the engine caps out around three thousand and goes no further. The car moves, but sluggishly, and overtaking is impossible. The check light is often on.The engine stumblesThe engine runs unevenly, the car shakes at idle, the exhaust note stutters. On the move the pull sags and consumption rises.Idle speed huntsThe tachometer needle wanders up and down with the car standing still: 1200, then 600. Sometimes the engine nearly stalls and picks up again.It jerks under accelerationAt steady throttle everything is fine, but under acceleration the car jerks or hesitates, as if the pedal was released for a moment.It cranks but will not startThe starter turns the engine over briskly, but it does not catch. Sometimes it catches and dies.It stalls at idleAt the lights, or when you lift off, the engine dies. It usually restarts straight away.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.