Conditions for Setting the DTC

WARNING: This page is about a different car, the 2009 GMC Sierra and 2009 Chevrolet Silverado. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: The ECM detects engine movement by sensing the airflow through the mass air flow (MAF) sensor, when airflow is greater than 3 grams per second, or by sensing camshaft position (CMP) sensor pulses.

The ECM detects that the starter is commanded ON and the engine has been cranking for more than 4 seconds without a CKP sensor pulse.
The ECM detects that the engine is running, but has not received a CKP sensor pulse for 2 of 10 engine cycles.