Conditions for Setting the DTC

WARNING: This page is about a different car, the 2009 GMC Yukon, 2009 Chevrolet Tahoe, 2009 Chevrolet Suburban, and 2009 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.

The ECM uses two ways to determine if the transfer case is in 4 low. The first way is to compare the transmission output speed sensor to the transfer case speed sensor in order to calculate transfer case range. The second way is to use a LAN message sent by the transfer case shift control module. If the first way and second way of determining this does not match while in 4 high then this DTC is set.
The ECM has detected 32 fail counts out of 400 samples.