DTC P1514: Throttle Body Performance: Description
WARNING: This page is about a different car, the 2002 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.
The Engine Control Module (ECM) uses the RPM and Throttle Position (TP) sensors to calculate an approximate MAP. The ECM compares this calculated value to the MAP sensor reading to determine if the throttle body is performing correctly. DTC P1514 will set if the ECM calculated MAP does not correlate to the current MAP sensor signal.