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 engine is running, but receives less than 53 or more than 63 crankshaft position sensor pulses, during each engine revolution, for 8 of 10 engine revolutions.
The ECM detects that the engine is running, but more than 25 crankshaft resyncs have occurred within 20 s.
The ECM detects that the engine has been running, but the crankshaft does not sync for 0.4 s.