P0605Powertrain
Internal control module ROM error
Where to start
A read-only memory error in the unit. Here the chance of a genuine failure is higher than with the neighbouring codes, but the order is the same: power and earths are checked BEFORE anyone talks about replacement.
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 thisControl unit faults on itself: P0600, P0601, P0603, P0606
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 engineControl module and its circuits
Number of the faultThe serial number inside that group — it does not say how serious the fault is
All codes in «Control module and its circuits»
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.