Separator Pulse and Engine ID Codes

SEPARATOR PULSE
A single 1/2 second separator pulse is issued 6-9 seconds after the last Key On Engine Off DTC. Then, 6-9 seconds after the single 1/2 second separator pulse, the Continuous Memory DTCs will be issued.

ENGINE IDENTIFICATION CODES (ID Codes)
Engine ID codes are issued at the beginning of the Engine Running Self-Test and are one-digit numbers represented by the number of pulses sent out. The engine ID code is equal to one-half the number of engine cylinders (i.e. 2 pulses = 4 cylinders). These codes are used to verify the proper PCM is installed and that the Self-Test has been entered.