Conditions for Setting the DTC

WARNING: This page is about a different car, the 2008 GMC Yukon XL, 2008 GMC Yukon, 2008 Chevrolet Tahoe, 2008 Chevrolet Suburban, and 2008 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, 4 high, and neutral. 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, 4 low, or neutral, then this DTC is set. This DTC sets if the gear ratio for 4 high or 4 low is indicated by the speed sensors.
The ECM has detected 32 fail counts out of 400 samples.