Conditions for Setting the DTC

WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2011 GMC Yukon XL, 2011 GMC Yukon, 2011 Chevrolet Tahoe, 2011 Chevrolet Suburban, and 2011 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.

The ECM detects that the starter is commanded ON and the engine has been cranking for greater than 4 s without a crankshaft position sensor pulse.
The ECM detects that the engine is running and the starter is not engaged and no crankshaft position sensor pulse for greater than 0.3 seconds.
The ECM detects that the engine is running, but has not received a crankshaft position sensor pulse for 2 of 10 engine cycles.