What This Keying Plug Does
The TE Connectivity CPC 206509-1 is a keying plug — an accessory that fits into the CPC connector housing to prevent mismating between circuits that share the same shell size. It's molded from white Polyphenylene Oxide (PPO) and is designed for use with CPC Connector Series 2 Size 20 DM and 20 DF contacts. In a multi-position harness, the keying plug blocks the cavity so only the matching keyed receptacle can mate, which keeps the wire-to-wire sequence correct without relying on labels or memory.
This plug is part of the TE CPC (Circular Plastic Connector) family. It's specific to Series 2 connectors that use Size 20 contacts — both the DM (machined) and DF (formed) contact types. It does not fit CPC Series 1 housings; the cavity geometry and keying slot are different between the two series. If you're working on a CPC Series 1 harness, this plug will not seat correctly.