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.

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 crankshaft position (CKP) sensor pulses.

The ECM detects that the starter is commanded on and the engine has been cranking for more than 4 seconds without a CMP sensor pulse.
The ECM detects that the engine has started, but did not receive a CMP sensor pulse during the first engine revolution.
The ECM detects that the engine is running, but does not receive a CMP sensor pulse for 800 of 1000 engine cycles.