DTC P0816
WARNING: This page is about a different car, the 2007 GMC Yukon XL, 2007 GMC Yukon, 2007 Cadillac Escalade EXT, 2007 Cadillac Escalade ESV, and 2007 Cadillac Escalade. However, it is still accessible from the selected car via links, so may be relevant.
The BCM detects a downshift request for 3 seconds in PARK, REVERSE, NEUTRAL, or D6- and for 600 seconds in PARK, REVERSE, NEUTRAL, D2, D4, or D6.