Action Taken When the DTC Sets

WARNING: This page is about a different car, the 2007 GMC Yukon XL, 2007 GMC Yukon, 2007 Chevrolet Tahoe, 2007 Chevrolet Suburban, and 2007 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.

The ECM does not illuminate the malfunction indicator lamp (MIL).
The ECM disables engine cranking.
The ECM stores the operating conditions when the Conditions for Setting the DTC are met. This information is stored as a Failure Record.
The ECM stores DTC P0851 in ECM history.