Terminal Position Assurance Locks
WARNING: This page is about a different car, the 2003 Oldsmobile Bravada, 2003 GMC Envoy XL, 2003 GMC Envoy, and 2003 Chevrolet TrailBlazer. However, it is still accessible from the selected car via links, so may be relevant.
The terminal position assurance (TPA) insert resembles the plastic combs used in the control module connectors. The TPA keeps the terminal securely seated in the connector body. Do not remove the TPA from the connector body unless you remove a terminal for replacement.