C0045Chassis
Wheel speed sensor — no signal (rear left at GM)
Where to start
⚠️ The number is read differently. In the GM numbering it is the REAR LEFT wheel; under SAE J2012 this number is not about wheel sensors at all. So the make and the reporting module come first, the spanner second. If it is the wheel, the order is the usual one: connector and wire at the hub, sensor last. The rear connector is easier to reach than the front, but sees more road salt.
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 thisWhy a scanner does not show ABS, airbag and gearbox faults
How the code is built
Letter — the systemChassis: brakes, ABS, suspension
Common or the maker's ownGeneric code: the same on every car
Number of the faultThe serial number inside that group — it does not say how serious the fault is
All codes in «Brakes, ABS and stability control»
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.