Crank Sense
WARNING: This page is about a different car, the 1988 Buick Riviera and 1988 Buick Reatta. However, it is still accessible from the selected car via links, so may be relevant.
Input is on EBCM pin No. 19. This provides a 12-volt signal to EBCM when ignition is in start position. The EBCM disengages the main relay when this signal is received. Missing crank sense will result in improper initialization of EBCM with ignition on.