Conditions for Setting the DTC

WARNING: This page is about a different car, the 2008 GMC Sierra and 2008 Chevrolet Silverado. However, it is still accessible from the selected car via links, so may be relevant.

IMPORTANT: The ECM detects engine movement by sensing the airflow through the MAF sensor when airflow is greater than 3 grams per second, or by sensing CMP sensor pulses.

The ECM detects that the starter is commanded on and the engine has been cranking for more than 3 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.