P050APowertrain
Cold start idle control system performance
Where to start
The cold-start idle speed is not following the plan. When cold the unit deliberately holds it higher so the catalyst warms up faster. If that does not happen, the usual culprit is the same coking in the throttle body or an air leak rather than a failure. ⚠️ The code gets in the way of an emissions test: some self-checks only run on a cold start.
A code is not a diagnosis. It says which check failed, not which part to replace. Clearing it without repair only means the car will report it again in a few trips.
How to put together a report a mechanic will actually read
Step by stepUnstable idle — how to find the cause
How the code is built
Letter — the systemPowertrain: engine and transmission
Common or the maker's ownGeneric code: the same on every car
Which part of the engineIdle and auxiliary systems
Number of the faultThe serial number inside that group — it does not say how serious the fault is
All codes in «Idle and auxiliary systems»
How the app helps
CarScan reads this code from your car through an OBD-II adapter, shows whether it is active now or only stored, names the module that reported it, and puts it into a plain-text report for your mechanic.