Theory Of Operation

The purpose of this diagnostic is to determine the reason of a reset after the reset occurred. Some of these are initiated by the Transmission Control Module (TCM) software and others may be caused by an under voltage condition. If the TCM detects a condition for initiating a reset, the reason of the reset is stored in an area of Random Access Memory (RAM) that is not initialized during TCM startup. Upon TCM startup this information is read out to store an appropriate Diagnostic Trouble Code (DTC) indicating the reason for the reset.

This diagnostic detects an under voltage reset of the TCM during normal operation (no engine start present). Under voltage resets during engine start will not be stored within the TCM.