Action Taken When The DTC Sets

WARNING: This page is about a different car, the 2002 GMC Sierra, 2002 GMC Cab & Chassis Sierra, 2002 Chevrolet Silverado, and 2002 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.

TCM performs the following actions if DTC is set:

When in a forward gear range and shifting is completed, the transmission will fail to another forward gear range when engine speed is reasonable.
When in Neutral or Reverse, the transmission fails to Neutral.
While diagnostic response is active, when the gearshift lever is moved from a forward gear range to Neutral or from a forward gear range to Reverse, then the transmission will shift to Neutral and a forward gear range cannot be re-attained.
DTC will be stored in the TCM history.
The TCM freezes shift adapts.
Illuminates the MIL when active.
TCM inhibits TCC engagement.