Please ensure that you have the latest drivers and firmware for your steering wheel by visiting Logitech's website. Also, make sure you have the Logitech Gaming Software running. This application must be running for games to use your Logitech steering wheel.
If you are already running the Logitech Gaming Software, go to the Options menu and select the Input Mapping tab. Scroll down to the Driving section. For each of the Steering, Throttle, and Brake inputs, select that line and press X to delete the current mappings. The, press Enter and follow the instructions to map your wheel inputs to those commands.