P0341 - Near Engine Start, CMP Fast Event Based Test
WARNING: This page is about a different car, the 2008 Pontiac G5 and 2008 Chevrolet Cobalt. However, it is still accessible from the selected car via links, so may be relevant.
The ECM detects the incorrect number of CMP sensor pulses in 2 revolutions of the crankshaft, which is usually within 1 second.