P2135Powertrain
Throttle position sensors A and B — correlation fault
Where to start
The two throttle position sensors disagree, and the control unit does not know which to believe — so it drops the car into limp mode with reduced power. Check the throttle connector and its wiring; the unit is replaced whole, as the sensors inside are usually not sold separately.
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 thisThrottle position sensor: P0121, P0122, P0123 and P2135
How the code is built
Letter — the systemPowertrain: engine and transmission
Common or the maker's ownGeneric code, second group
Which part of the engineFuel and air metering
Number of the faultThe serial number inside that group — it does not say how serious the fault is
All codes in «Throttle and accelerator pedal»
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.