Battery Feed
WARNING: This page is about a different car, the 2003 Jeep Liberty. However, it is still accessible from the selected car via links, so may be relevant.
A fused, direct battery feed, to the TCM is used for continuous power. This battery voltage is necessary to retain adaptive learn values in the TCM's RAM (Random Access Memory). When the battery (B+) is disconnected, this memory is lost. When the battery (B+) is restored, this memory loss is detected by the TCM and a Diagnostic Trouble Code (DTC) is set.