Conditions for Setting the DTC
WARNING: This page is about a different car, the 2007 GMC Yukon XL and 2007 Chevrolet Suburban. However, it is still accessible from the selected car via links, so may be relevant.
The following condition occurs 5 times during the same trip:
The TCM commands 2nd gear and the gear ratio indicates 1st gear, 2.42:1 to 2.52:1 for 2.25 seconds or greater.