CarScan
P0443Powertrain

Evaporative emission purge control valve circuit malfunction

Where to start

The purge valve circuit. Along with checking the connector, listen to the valve with the ignition on: a working one clicks quietly. A valve stuck open gives hunting idle and a hard start after refuelling.

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

We have a detailed piece on thisThe fuel cap: codes P0455, P0442 and P0457

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 engineEmission controls: catalyst, EGR, fuel vapour
Number of the faultThe serial number inside that group — it does not say how serious the fault is

All codes in «Canister and purge valves»

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.

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.

See what the app does

Unfamiliar word? Open the glossary

What the letter and the four digits mean