Keyword 2000 Serial Data Circuit: Notes

WARNING: This page is about a different car, the 2007 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.

The Keyword protocols utilizes a single wire bi-directional data line between the modules and the scan tool. The message structure is a request and response arrangement. Keyword 2000 is used for scan tool diagnostics only. The modules do not exchange data on these systems. They are two independent Keyword serial data circuits connected to data link connector (DLC) terminals 7 and 12. The following modules communicate with scan tool through Keyword 2000 serial data circuits:

Keyword serial data to DLC terminal 7

Transmission control module (TCM), w/L61
Engine control module (ECM)/powertrain control module (PCM)