P0544Powertrain
Exhaust gas temperature sensor (bank 1) — circuit malfunction
Where to start
The exhaust gas temperature sensor circuit. The sensor sits in the hottest place on the car, and its wire hardens and breaks right at the connector over time — that is where to look. The sensor itself is usually fine.
What to watch in live data
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 thisAdBlue and urea: codes P203B, P2047, P204F, P20EE
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.