DTC P1345: Crankshaft/Camshaft Position Sensor Correlation: Description
WARNING: This page is about a different car, the 2003 Oldsmobile Bravada, 2003 GMC Envoy XL, 2003 GMC Envoy, and 2003 Chevrolet TrailBlazer. However, it is still accessible from the selected car via links, so may be relevant.
The Powertrain Control Module (PCM) uses the crankshaft sensor and the camshaft sensor information to monitor the correlation between the crankshaft and camshaft positions. This DTC will set if the deviation between the crankshaft and camshaft exceeds a calibrated amount.