The purpose of the GM ECM Harness Adapter board (Fig. 1) is to allow the installation of a 1227747 or 1228746 ECM into a Cross-Fire Injection equipped Corvette, Camaro, or Firebird without the need for extensive modifying of the original wiring harness in the car.

The Cross-Fire equipped cars came from the factory with an ECM that uses edge-card type connectors (Fig. 2) for the wiring harness.

Vehicles equipped with an 1227747 or 1228746 ECM use a pin-and-socket type of connector (Fig. 3)for the wiring harness.

By removing the original pin-and-socket connector from the ECM main board and replacing it with the Harness Adapter Module, the ECM can connect directly to the original wiring harness in the car without the need for any wire cutting or splicing, or the need for any "pigtail" adapters. See "installation"