PID 11%

Throttle position

How far the throttle is open, from the sensor on the throttle itself. This is what actually happens. Two neighbours are easy to confuse with it: PID 4C is how far the unit ASKS the throttle to open, and PID 45 is the same position as a share of full travel. A gap between «asked» and «actual» points straight at a coked throttle body or a tired actuator.

What is normal

A few percent with the pedal released, about 80–100 % fully pressed.

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

P0121Throttle position sensor A circuit range/performance P0122Throttle position sensor A circuit low input P0123Throttle position sensor A circuit high input

We have a detailed piece on thisElectronic throttle and pedal: P2119, P2122, P2138, P2110

Step by stepUnstable idle — how to find the cause

Codes behind this reading

If the value is out of range, the unit usually says so with one of these codes.

P0121Throttle position sensor A circuit range/performance P0122Throttle position sensor A circuit low input P0123Throttle position sensor A circuit high input P2100Throttle actuator — circuit open P2101Throttle actuator — range or performance fault

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.

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.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.The car has lost powerThe car moves, but sluggishly: flooring the throttle changes nothing, the revs climb reluctantly. Often the lamp is on as well.Cruise control stopped engagingThe button clicks but cruise never takes the speed — or it drops out after a few seconds.

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.

What the app does